From 9caedfa8c124de81745d29bf5a39ff69f7a30756 Mon Sep 17 00:00:00 2001
From: acanas <acanas@ugr.es>
Date: Thu, 31 Mar 2022 09:49:57 +0200
Subject: [PATCH] Version 21.88:    Mar 31, 2022  Working on design of dark
 theme.

---
 swad_HTML.c               | 28 ++++++++++++++++++++++++----
 swad_HTML.h               |  3 ++-
 swad_ID.c                 |  4 ++--
 swad_MFU.c                | 10 ++++++----
 swad_agenda.c             |  4 ++--
 swad_assignment.c         |  4 ++--
 swad_attendance.c         | 11 +++++------
 swad_browser.c            | 35 ++++++++++++++++++-----------------
 swad_building.c           |  4 ++--
 swad_button.c             | 12 ++++++------
 swad_center.c             |  7 ++++---
 swad_center_config.c      |  6 +++---
 swad_changelog.h          |  3 ++-
 swad_chat.c               |  7 ++++---
 swad_connected.c          | 14 ++++++++------
 swad_country.c            | 12 ++++++------
 swad_country_config.c     |  6 +++---
 swad_course.c             | 34 +++++++++++++++++-----------------
 swad_course_config.c      |  6 +++---
 swad_date.c               |  8 ++++----
 swad_degree.c             |  4 ++--
 swad_degree_config.c      |  6 +++---
 swad_degree_type.c        |  4 ++--
 swad_department.c         |  4 ++--
 swad_enrolment.c          |  4 ++--
 swad_exam.c               |  8 ++++----
 swad_exam_result.c        |  5 ++---
 swad_exam_session.c       |  3 ++-
 swad_follow.c             | 14 +++++++-------
 swad_forum.c              | 16 +++++++---------
 swad_game.c               |  8 ++++----
 swad_group.c              |  4 ++--
 swad_hierarchy.c          | 26 +++++++++++++-------------
 swad_hierarchy_config.c   |  2 +-
 swad_holiday.c            |  4 ++--
 swad_info.c               |  7 ++++---
 swad_institution.c        | 12 ++++++------
 swad_institution_config.c |  4 ++--
 swad_layout.c             |  7 +++----
 swad_link.c               |  2 +-
 swad_mail.c               |  4 ++--
 swad_match.c              | 16 +++++++++-------
 swad_match_result.c       |  5 ++---
 swad_menu.c               |  2 +-
 swad_message.c            | 15 ++++++++-------
 swad_notice.c             |  3 ++-
 swad_notification.c       | 14 +++++++-------
 swad_pagination.c         | 29 +++++++++++++----------------
 swad_photo.c              | 10 +++++-----
 swad_place.c              |  4 ++--
 swad_profile.c            | 15 ++++++++-------
 swad_project.c            |  8 ++++----
 swad_question.c           |  4 ++--
 swad_record.c             | 14 ++++++++------
 swad_room.c               |  4 ++--
 swad_statistic.c          |  8 +++++---
 swad_survey.c             |  5 +++--
 swad_system_config.c      |  2 +-
 swad_tab.c                |  4 ++--
 swad_theme.c              | 11 -----------
 swad_timeline_comment.c   |  9 +++------
 swad_timeline_form.c      |  8 ++++----
 swad_timeline_note.c      | 12 +++++-------
 swad_timeline_post.c      |  3 ++-
 swad_user.c               |  9 +++++----
 65 files changed, 299 insertions(+), 281 deletions(-)

diff --git a/swad_HTML.c b/swad_HTML.c
index 3cf9c61d..aeca3015 100644
--- a/swad_HTML.c
+++ b/swad_HTML.c
@@ -1484,15 +1484,35 @@ void HTM_BUTTON_OnMouseDown_Begin (const char *Title,const char *Class)
    HTM_BUTTON_NestingLevel++;
   }
 
-void HTM_BUTTON_OnSubmit_Begin (const char *Title,const char *Class,const char *OnSubmit)
+void HTM_BUTTON_OnSubmit_Begin (const char *Title,const char *OnSubmit,
+		                const char *fmt,...)
   {
+   va_list ap;
+   int NumBytesPrinted;
+   char *Attr;
+
    HTM_Txt ("<button type=\"submit\"");
    if (Title)
       if (Title[0])
          HTM_TxtF (" title=\"%s\"",Title);
-   if (Class)
-      if (Class[0])
-         HTM_TxtF (" class=\"%s\"",Class);
+
+   if (fmt)
+     {
+      if (fmt[0])
+	{
+	 va_start (ap,fmt);
+	 NumBytesPrinted = vasprintf (&Attr,fmt,ap);
+	 va_end (ap);
+	 if (NumBytesPrinted < 0)	// -1 if no memory or any other error
+	    Err_NotEnoughMemoryExit ();
+
+	 /***** Print attributes *****/
+	 HTM_SPTxt (Attr);
+
+	 free (Attr);
+	}
+     }
+
    if (OnSubmit)	// JavaScript function to be called before submitting the form
       if (OnSubmit[0])
          HTM_TxtF (" onsubmit=\"%s;\"",OnSubmit);
diff --git a/swad_HTML.h b/swad_HTML.h
index 38cc3ab9..e297fe7b 100644
--- a/swad_HTML.h
+++ b/swad_HTML.h
@@ -164,7 +164,8 @@ void HTM_INPUT_CHECKBOX (const char *Name,HTM_SubmitOnChange_t SubmitOnChange,
 		         const char *fmt,...);
 
 void HTM_BUTTON_OnMouseDown_Begin (const char *Title,const char *Class);
-void HTM_BUTTON_OnSubmit_Begin (const char *Title,const char *Class,const char *OnSubmit);
+void HTM_BUTTON_OnSubmit_Begin (const char *Title,const char *OnSubmit,
+		                const char *fmt,...);
 void HTM_BUTTON_OnClick_Begin (const char *Title,const char *Class,const char *OnClick);
 void HTM_BUTTON_End (void);
 
diff --git a/swad_ID.c b/swad_ID.c
index ddde7497..7311d658 100644
--- a/swad_ID.c
+++ b/swad_ID.c
@@ -426,8 +426,8 @@ static void ID_PutLinkToConfirmID (struct UsrData *UsrDat,unsigned NumID,
       Par_PutHiddenParamString (NULL,"UsrID",UsrDat->IDs.List[NumID].ID);
 
       /***** Put link *****/
-      HTM_BUTTON_OnSubmit_Begin (Txt_Confirm_ID,
-                                 The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme],NULL);
+      HTM_BUTTON_OnSubmit_Begin (Txt_Confirm_ID,NULL,
+                                 "class=\"%s\"",The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme]);
 	 Ico_PutIconTextLink ("check.svg",Ico_BLACK,Txt_Confirm_ID);
       HTM_BUTTON_End ();
 
diff --git a/swad_MFU.c b/swad_MFU.c
index 66a4a891..aeeba548 100644
--- a/swad_MFU.c
+++ b/swad_MFU.c
@@ -220,8 +220,8 @@ void MFU_WriteBigMFUActions (struct MFU_ListMFUActions *ListMFUActions)
 		  HTM_LI_Begin ("class=\"ICO_HIGHLIGHT\"");
 		     Frm_BeginForm (Action);
 			HTM_BUTTON_OnSubmit_Begin (TabMenuStr,
-			                           The_ClassFormLinkInBoxNoWrap[Gbl.Prefs.Theme],
-			                           NULL);
+			                           NULL,
+			                           "class=\"%s\"",The_ClassFormLinkInBoxNoWrap[Gbl.Prefs.Theme]);
 			   HTM_IMG (Gbl.Prefs.URLIconSet,Act_GetIcon (Action),MenuStr,
 				    "class=\"%s\"",
 				    Ico_ClassColor[Ico_BLACK][Gbl.Prefs.Theme]);
@@ -265,7 +265,8 @@ void MFU_WriteSmallMFUActions (struct MFU_ListMFUActions *ListMFUActions)
                   The_Colors[Gbl.Prefs.Theme]);
 
       Frm_BeginForm (ActMFUAct);
-	 HTM_BUTTON_OnSubmit_Begin (Txt_My_frequent_actions,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_My_frequent_actions,NULL,
+	                            "class=\"BT_LINK\"");
 	    HTM_TxtF ("%s",Txt_Frequent_ACTIONS);
 	 HTM_BUTTON_End ();
       Frm_EndForm ();
@@ -290,7 +291,8 @@ void MFU_WriteSmallMFUActions (struct MFU_ListMFUActions *ListMFUActions)
 	       /* Icon and text */
 	       HTM_LI_Begin ("class=\"ICO_HIGHLIGHT\"");
 		  Frm_BeginForm (Action);
-		     HTM_BUTTON_OnSubmit_Begin (TabMenuStr,"BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (TabMenuStr,NULL,
+		                                "class=\"BT_LINK\"");
 			HTM_IMG (Gbl.Prefs.URLIconSet,Act_GetIcon (Action),MenuStr,
 				 "class=\"%s\"",
 				 Ico_ClassColor[Ico_BLACK][Gbl.Prefs.Theme]);
diff --git a/swad_agenda.c b/swad_agenda.c
index 4079bd65..6b7f67db 100644
--- a/swad_agenda.c
+++ b/swad_agenda.c
@@ -663,8 +663,8 @@ static void Agd_WriteHeaderListEvents (const struct Agd_Agenda *Agenda,
 				   Agenda->CurrentPage,
 				   -1L);
 
-	       HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],
-	                                  "BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],NULL,
+	                                  "class=\"BT_LINK\"");
 		  if (Order == Agenda->SelectedOrder)
 		     HTM_U_Begin ();
 
diff --git a/swad_assignment.c b/swad_assignment.c
index 4b4dca8d..ad74483e 100644
--- a/swad_assignment.c
+++ b/swad_assignment.c
@@ -241,8 +241,8 @@ static void Asg_PutHeadForSeeing (struct Asg_Assignments *Assignments,
 		  Dat_PutHiddenParamOrder (Order);
 
 	          /* Begin link to select order */
-		  HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],NULL,
+		                             "class=\"BT_LINK\"");
 		  if (Order == Assignments->SelectedOrder)
 		     HTM_U_Begin ();
 	      }
diff --git a/swad_attendance.c b/swad_attendance.c
index 5defa294..ac51b831 100644
--- a/swad_attendance.c
+++ b/swad_attendance.c
@@ -269,8 +269,8 @@ static void Att_ShowAllAttEvents (struct Att_Events *Events)
 			Pag_PutHiddenParamPagNum (Pag_ATT_EVENTS,Events->CurrentPage);
 			Dat_PutHiddenParamOrder (Order);
 
-			HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],
-			                           "BT_LINK",NULL);
+			HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],NULL,
+			                           "class=\"BT_LINK\"");
 
 			   if (Order == Events->SelectedOrder)
 			      HTM_U_Begin ();
@@ -1864,7 +1864,7 @@ static void Att_PutLinkAttEvent (struct Att_Event *AttEvent,
       Att_PutParamsCodGrps (AttEvent->AttCod);
 
       /***** Link to view attendance event *****/
-      HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+      HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	 HTM_Txt (Txt);
       HTM_BUTTON_End ();
 
@@ -2782,9 +2782,8 @@ static void Att_ListEventsToSelect (const struct Att_Events *Events,
       if (NormalView)
 	{
 	 HTM_DIV_Begin ("class=\"UPD\"");
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Update_attendance,
-				       The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme],
-				       NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Update_attendance,NULL,
+				       "class=\"%s\"",The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme]);
 	       Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Update_attendance);
 	    HTM_BUTTON_End ();
 	 HTM_DIV_End ();
diff --git a/swad_browser.c b/swad_browser.c
index c0a2dd3e..25bd9984 100644
--- a/swad_browser.c
+++ b/swad_browser.c
@@ -3278,8 +3278,8 @@ static void Brw_ShowDataOwnerAsgWrk (struct UsrData *UsrDat)
 	    /***** Show user's name *****/
 	    HTM_BR ();
 
-	    HTM_BUTTON_OnSubmit_Begin (Txt_View_record_for_this_course,
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_View_record_for_this_course,NULL,
+	                               "class=\"BT_LINK\"");
 	       HTM_Txt (UsrDat->Surname1);
 	       if (UsrDat->Surname2[0])
 		  HTM_TxtF ("&nbsp;%s",UsrDat->Surname2);
@@ -5316,9 +5316,9 @@ static void Brw_WriteFileName (unsigned Level,bool IsPublic)
 
 	       /* Link to the form and to the file */
 	       HTM_BUTTON_OnSubmit_Begin ((Gbl.FileBrowser.Type == Brw_SHOW_MRK_CRS ||
-					  Gbl.FileBrowser.Type == Brw_SHOW_MRK_GRP) ? Txt_Check_marks_in_the_file :
-										      Txt_Download,
-					  "BT_LINK FILENAME",NULL);
+					   Gbl.FileBrowser.Type == Brw_SHOW_MRK_GRP) ? Txt_Check_marks_in_the_file :
+										       Txt_Download,
+					  NULL,"class=\"BT_LINK FILENAME\"");
 		  HTM_Txt (FileNameToShow);
 	       HTM_BUTTON_End ();
 
@@ -8545,8 +8545,8 @@ static void Brw_WriteBigLinkToDownloadFile (const char *URL,
 	 Brw_PutImplicitParamsFileBrowser (&Gbl.FileBrowser.FilFolLnk);
 
 	 /* Begin link */
-	 HTM_BUTTON_OnSubmit_Begin (Txt_Check_marks_in_the_file,
-	                            ClassFilename[Gbl.Prefs.Theme],NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_Check_marks_in_the_file,NULL,
+	                            "class=\"%s\"",ClassFilename[Gbl.Prefs.Theme]);
 
 	    if (FileMetadata->FilFolLnk.Type == Brw_IS_FILE)
 	       Brw_PutIconFile (FileMetadata->FilFolLnk.Name,
@@ -8610,7 +8610,8 @@ static void Brw_WriteSmallLinkToDownloadFile (const char *URL,
 	 Brw_PutImplicitParamsFileBrowser (&Gbl.FileBrowser.FilFolLnk);
 
 	 /* Begin link */
-	 HTM_BUTTON_OnSubmit_Begin (Txt_Check_marks_in_the_file,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_Check_marks_in_the_file,NULL,
+	                            "class=\"BT_LINK\"");
 
 	    /* Name of the file of marks */
 	    HTM_Txt (FileNameToShow);
@@ -10003,8 +10004,8 @@ static void Brw_WriteRowDocData (unsigned *NumDocsNotHidden,MYSQL_ROW row)
 	      {
 	       Frm_BeginFormGoTo (ActSeeInsInf);
 		  Deg_PutParamDegCod (InsCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (InsShortName),
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (InsShortName),NULL,
+		                             "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     Lgo_DrawLogo (HieLvl_INS,InsCod,InsShortName,20,"BT_LINK LT",true);
 		     HTM_TxtF ("&nbsp;%s",InsShortName);
@@ -10020,8 +10021,8 @@ static void Brw_WriteRowDocData (unsigned *NumDocsNotHidden,MYSQL_ROW row)
 	      {
 	       Frm_BeginFormGoTo (ActSeeCtrInf);
 		  Deg_PutParamDegCod (CtrCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (CtrShortName),
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (CtrShortName),NULL,
+		                             "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     Lgo_DrawLogo (HieLvl_CTR,CtrCod,CtrShortName,20,"LT",true);
 		     HTM_TxtF ("&nbsp;%s",CtrShortName);
@@ -10037,8 +10038,8 @@ static void Brw_WriteRowDocData (unsigned *NumDocsNotHidden,MYSQL_ROW row)
 	      {
 	       Frm_BeginFormGoTo (ActSeeDegInf);
 		  Deg_PutParamDegCod (DegCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (DegShortName),
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (DegShortName),NULL,
+		                             "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     Lgo_DrawLogo (HieLvl_DEG,DegCod,DegShortName,20,"LT",true);
 		     HTM_TxtF ("&nbsp;%s",DegShortName);
@@ -10054,8 +10055,8 @@ static void Brw_WriteRowDocData (unsigned *NumDocsNotHidden,MYSQL_ROW row)
 	      {
 	       Frm_BeginFormGoTo (ActSeeCrsInf);
 		  Crs_PutParamCrsCod (CrsCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (CrsShortName),
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (CrsShortName),NULL,
+		                             "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     HTM_Txt (CrsShortName);
 		  HTM_BUTTON_End ();
@@ -10160,7 +10161,7 @@ static void Brw_WriteRowDocData (unsigned *NumDocsNotHidden,MYSQL_ROW row)
 					 FileMetadata.FilCod);
 
 	    /* File or folder icon */
-	    HTM_BUTTON_OnSubmit_Begin (FileNameToShow,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (FileNameToShow,NULL,"class=\"BT_LINK\"");
 	       switch (FileMetadata.FilFolLnk.Type)
 	         {
 		  case Brw_IS_FILE:
diff --git a/swad_building.c b/swad_building.c
index 752cdfac..f58c1a95 100644
--- a/swad_building.c
+++ b/swad_building.c
@@ -128,8 +128,8 @@ void Bld_SeeBuildings (void)
                HTM_TH_Begin (HTM_HEAD_LEFT);
 		  Frm_BeginForm (ActSeeBld);
 		     Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		     HTM_BUTTON_OnSubmit_Begin (Txt_BUILDINGS_HELP_ORDER[Order],
-		                                "BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Txt_BUILDINGS_HELP_ORDER[Order],NULL,
+		                                "class=\"BT_LINK\"");
 			if (Order == Buildings.SelectedOrder)
 			   HTM_U_Begin ();
 			HTM_Txt (Txt_BUILDINGS_ORDER[Order]);
diff --git a/swad_button.c b/swad_button.c
index 7f1715fc..f750c65f 100644
--- a/swad_button.c
+++ b/swad_button.c
@@ -68,7 +68,7 @@ void Btn_PutButtonInline (Btn_Button_t Button,const char *TxtButton)
 void Btn_PutCreateButton (const char *TxtButton)
   {
    HTM_DIV_Begin ("class=\"CM\"");
-      HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT BT_CREATE",NULL);
+      HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_SUBMIT BT_CREATE\"");
 	 HTM_Txt (TxtButton);
       HTM_BUTTON_End ();
    HTM_DIV_End ();
@@ -76,7 +76,7 @@ void Btn_PutCreateButton (const char *TxtButton)
 
 void Btn_PutCreateButtonInline (const char *TxtButton)
   {
-   HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT_INLINE BT_CREATE",NULL);
+   HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_SUBMIT_INLINE BT_CREATE\"");
       HTM_Txt (TxtButton);
    HTM_BUTTON_End ();
   }
@@ -84,7 +84,7 @@ void Btn_PutCreateButtonInline (const char *TxtButton)
 void Btn_PutConfirmButton (const char *TxtButton)
   {
    HTM_DIV_Begin ("class=\"CM\"");
-      HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT BT_CONFIRM",NULL);
+      HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_SUBMIT BT_CONFIRM\"");
 	 HTM_Txt (TxtButton);
       HTM_BUTTON_End ();
    HTM_DIV_End ();
@@ -92,7 +92,7 @@ void Btn_PutConfirmButton (const char *TxtButton)
 
 void Btn_PutConfirmButtonInline (const char *TxtButton)
   {
-   HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT_INLINE BT_CONFIRM",NULL);
+   HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_SUBMIT_INLINE BT_CONFIRM\"");
       HTM_Txt (TxtButton);
    HTM_BUTTON_End ();
   }
@@ -100,7 +100,7 @@ void Btn_PutConfirmButtonInline (const char *TxtButton)
 void Btn_PutRemoveButton (const char *TxtButton)
   {
    HTM_DIV_Begin ("class=\"CM\"");
-      HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT BT_REMOVE",NULL);
+      HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_SUBMIT BT_REMOVE\"");
 	 HTM_Txt (TxtButton);
       HTM_BUTTON_End ();
    HTM_DIV_End ();
@@ -108,7 +108,7 @@ void Btn_PutRemoveButton (const char *TxtButton)
 
 void Btn_PutRemoveButtonInline (const char *TxtButton)
   {
-   HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT_INLINE BT_REMOVE",NULL);
+   HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_SUBMIT_INLINE BT_REMOVE\"");
       HTM_Txt (TxtButton);
    HTM_BUTTON_End ();
   }
diff --git a/swad_center.c b/swad_center.c
index a6e8e313..93534bf0 100644
--- a/swad_center.c
+++ b/swad_center.c
@@ -190,7 +190,8 @@ void Ctr_DrawCenterLogoAndNameWithLink (struct Ctr_Center *Ctr,Act_Action_t Acti
       Ctr_PutParamCtrCod (Ctr->CtrCod);
 
       /***** Link to action *****/
-      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Ctr->FullName),"BT_LINK",NULL);
+      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Ctr->FullName),NULL,
+                                 "class=\"BT_LINK\"");
       Str_FreeGoToTitle ();
 
 	 /***** Center logo and name *****/
@@ -1450,8 +1451,8 @@ static void Ctr_PutHeadCentersForSeeing (bool OrderSelectable)
 	      {
 	       Frm_BeginForm (ActSeeCtr);
 		  Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_CENTERS_HELP_ORDER[Order],
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_CENTERS_HELP_ORDER[Order],NULL,
+					     "class=\"BT_LINK\"");
 		     if (Order == Gbl.Hierarchy.Ctrs.SelectedOrder)
 			HTM_U_Begin ();
 	      }
diff --git a/swad_center_config.c b/swad_center_config.c
index 623fde8a..ff321eda 100644
--- a/swad_center_config.c
+++ b/swad_center_config.c
@@ -597,8 +597,8 @@ static void CtrCfg_Institution (bool PrintView,bool PutForm)
 	      {
 	       Frm_BeginFormGoTo (ActSeeInsInf);
 		  Ins_PutParamInsCod (Gbl.Hierarchy.Ins.InsCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Ins.ShrtName),
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Ins.ShrtName),NULL,
+		                             "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 	      }
 
@@ -776,7 +776,7 @@ static void CtrCfg_NumDegs (void)
 	    Ctr_PutParamCtrCod (Gbl.Hierarchy.Ctr.CtrCod);
 	    if (asprintf (&Title,Txt_Degrees_of_CENTER_X,Gbl.Hierarchy.Ctr.ShrtName) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	    free (Title);
 	       HTM_Unsigned (Deg_GetCachedNumDegsInCtr (Gbl.Hierarchy.Ctr.CtrCod));
 	    HTM_BUTTON_End ();
diff --git a/swad_changelog.h b/swad_changelog.h
index 43b0c5fa..1d1fed8b 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -606,10 +606,11 @@ TODO: Fix bug: error al enviar un mensaje a dos recipientes, error on duplicate
 
 TODO: Attach pdf files in multimedia.
 */
-#define Log_PLATFORM_VERSION	"SWAD 21.87.1 (2022-03-30)"
+#define Log_PLATFORM_VERSION	"SWAD 21.88 (2022-03-31)"
 #define CSS_FILE		"swad21.86.7.css"
 #define JS_FILE			"swad21.78.2.js"
 /*
+	Version 21.88:    Mar 31, 2022  Working on design of dark theme. (323802 lines)
 	Version 21.87.1:  Mar 30, 2022  Working on design of dark theme. (323786 lines)
 	Version 21.87:    Mar 30, 2022  Working on design of dark theme. (323833 lines)
 	Version 21.86.8:  Mar 29, 2022  Working on design of dark theme. (323834 lines)
diff --git a/swad_chat.c b/swad_chat.c
index c0f76b1e..719009a3 100644
--- a/swad_chat.c
+++ b/swad_chat.c
@@ -303,7 +303,7 @@ void Cht_ShowListOfChatRoomsWithUsrs (void)
 static void Cht_WriteLinkToChat1 (const char *RoomCode,const char *RoomShrtName,const char *RoomFullName,
                                   unsigned Level,bool IsLastItemInLevel[1 + Cht_CHAT_MAX_LEVELS])
   {
-   extern const char *The_ClassFormLinkInBox[The_NUM_THEMES];
+   extern const char *The_Colors[The_NUM_THEMES];
 
    /***** Begin list item *****/
    HTM_LI_Begin (NULL);
@@ -316,8 +316,9 @@ static void Cht_WriteLinkToChat1 (const char *RoomCode,const char *RoomShrtName,
 	 Cht_WriteParamsRoomCodeAndNames (RoomCode,RoomShrtName,RoomFullName);
 
 	 /* Begin button */
-	 HTM_BUTTON_OnSubmit_Begin (RoomFullName,
-	                            The_ClassFormLinkInBox[Gbl.Prefs.Theme],NULL);
+	 HTM_BUTTON_OnSubmit_Begin (RoomFullName,NULL,
+	                            "class=\"BT_LINK FORM_IN_%s\"",
+	                            The_Colors[Gbl.Prefs.Theme]);
   }
 
 static void Cht_WriteLinkToChat2 (const char *RoomCode,const char *RoomFullName)
diff --git a/swad_connected.c b/swad_connected.c
index 00ccc8ac..7b8f66bc 100644
--- a/swad_connected.c
+++ b/swad_connected.c
@@ -181,7 +181,8 @@ void Con_ShowGlobalConnectedUsrs (void)
       Frm_BeginFormUnique (ActLstCon);	// Must be unique because
 					// the list of connected users
 					// is dynamically updated via AJAX
-	 HTM_BUTTON_OnSubmit_Begin (Txt_Connected_users,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_Connected_users,NULL,
+	                            "class=\"BT_LINK\"");
 
 	    /* Write total number of sessions */
 	    HTM_TxtF ("%u&nbsp;%s",Gbl.Session.NumSessions,
@@ -335,7 +336,8 @@ void Con_ShowConnectedUsrsBelongingToCurrentCrs (void)
       Frm_BeginFormUnique (ActLstCon);	// Must be unique because
 					// the list of connected users
 					// is dynamically updated via AJAX
-	 HTM_BUTTON_OnSubmit_Begin (Txt_Connected_users,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_Connected_users,NULL,
+	                            "class=\"BT_LINK\"");
 	    Str_Copy (CourseName,Gbl.Hierarchy.Crs.ShrtName,sizeof (CourseName) - 1);
 	    Con_GetNumConnectedWithARoleBelongingToCurrentScope (Rol_UNK,&Usrs);
 	    HTM_TxtF ("%u %s %s",Usrs.NumUsrs,Txt_from,CourseName);
@@ -618,8 +620,8 @@ static void Con_WriteRowConnectedUsrOnRightColumn (Rol_Role_t Role)
 	    Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
 
 	    HTM_DIV_Begin ("class=\"CON_NAME_NARROW\"");	// Limited width
-	       HTM_BUTTON_OnSubmit_Begin (Txt_View_record_for_this_course,
-	                                  "BT_LINK LT",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_View_record_for_this_course,NULL,
+	                                  "class=\"BT_LINK LT\"");
 		  Usr_WriteFirstNameBRSurnames (UsrDat);
 	       HTM_BUTTON_End ();
 	    HTM_DIV_End ();
@@ -728,8 +730,8 @@ static void Con_ShowConnectedUsrsCurrentLocationOneByOneOnMainZone (Rol_Role_t R
 		    }
 
 		  if (PutLinkToRecord)
-		     HTM_BUTTON_OnSubmit_Begin (UsrDat.FullName,
-						"BT_LINK LT",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (UsrDat.FullName,NULL,
+						"class=\"BT_LINK LT\"");
 		  Usr_WriteFirstNameBRSurnames (&UsrDat);
 		  if (PutLinkToRecord)
 		     HTM_BUTTON_End ();
diff --git a/swad_country.c b/swad_country.c
index 3c7755c9..85c84317 100644
--- a/swad_country.c
+++ b/swad_country.c
@@ -369,8 +369,8 @@ static void Cty_PutHeadCountriesForSeeing (bool OrderSelectable)
 	      {
 	       Frm_BeginForm (ActSeeCty);
 		  Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_COUNTRIES_HELP_ORDER[Order],
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_COUNTRIES_HELP_ORDER[Order],NULL,
+					     "class=\"BT_LINK\"");
 		     if (Order == Gbl.Hierarchy.Ctys.SelectedOrder)
 			HTM_U_Begin ();
 	      }
@@ -520,8 +520,8 @@ void Cty_DrawCountryMapAndNameWithLink (struct Cty_Countr *Cty,Act_Action_t Acti
       HTM_DIV_Begin ("class=\"%s\"",ClassContainer);
 
 	 /***** Link to action *****/
-	 HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Cty->Name[Gbl.Prefs.Language]),
-				    "BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Cty->Name[Gbl.Prefs.Language]),NULL,
+				    "class=\"BT_LINK\"");
 	 Str_FreeGoToTitle ();
 
 	    /***** Draw country map *****/
@@ -925,8 +925,8 @@ void Cty_WriteCountryName (long CtyCod)
       /***** Write country name with link to country information *****/
       Frm_BeginForm (ActSeeCtyInf);
 	 Cty_PutParamCtyCod (CtyCod);
-	 HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeCtyInf),
-	                            "BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeCtyInf),NULL,
+	                            "class=\"BT_LINK\"");
 	    HTM_Txt (CtyName);
 	 HTM_BUTTON_End ();
       Frm_EndForm ();
diff --git a/swad_country_config.c b/swad_country_config.c
index ffb309a2..e953e91d 100644
--- a/swad_country_config.c
+++ b/swad_country_config.c
@@ -375,8 +375,8 @@ static void CtyCfg_Platform (bool PrintView)
 	 if (!PrintView)
 	   {
 	    Frm_BeginFormGoTo (ActSeeSysInf);
-	       HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Cfg_PLATFORM_SHORT_NAME),
-					  "BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Cfg_PLATFORM_SHORT_NAME),NULL,
+					  "class=\"BT_LINK\"");
 	       Str_FreeGoToTitle ();
 	   }
 	 Ico_PutIcon ("swad64x64.png",Ico_UNCHANGED,Cfg_PLATFORM_FULL_NAME,"ICO20x20");
@@ -486,7 +486,7 @@ static void CtyCfg_NumInss (void)
 	    if (asprintf (&Title,Txt_Institutions_of_COUNTRY_X,
 	                  Gbl.Hierarchy.Cty.Name[Gbl.Prefs.Language]) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	    free (Title);
 	       HTM_Unsigned (Ins_GetCachedNumInssInCty (Gbl.Hierarchy.Cty.CtyCod));
 	    HTM_BUTTON_End ();
diff --git a/swad_course.c b/swad_course.c
index 86cdb886..479bc754 100644
--- a/swad_course.c
+++ b/swad_course.c
@@ -191,7 +191,7 @@ static void Crs_WriteListMyCoursesToSelectOne (void)
 						  ClassNormal);
 	    Frm_BeginForm (ActMyCrs);
 	       Cty_PutParamCtyCod (-1L);
-	       HTM_BUTTON_OnSubmit_Begin (Txt_System,"BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_System,NULL,"class=\"BT_LINK\"");
 		  Ico_PutIcon ("sitemap.svg",Ico_BLACK,Txt_System,"ICO16x16");
 		  HTM_TxtF ("&nbsp;%s",Txt_System);
 	       HTM_BUTTON_End ();
@@ -221,8 +221,8 @@ static void Crs_WriteListMyCoursesToSelectOne (void)
 	       Lay_IndentDependingOnLevel (1,IsLastItemInLevel);
 	       Frm_BeginForm (ActMyCrs);
 		  Cty_PutParamCtyCod (Hie.Cty.CtyCod);
-		  HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeCtyInf),
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeCtyInf),NULL,
+					     "class=\"BT_LINK\"");
 		     Cty_DrawCountryMap (&Hie.Cty,"ICO16x16");
 		     HTM_TxtF ("&nbsp;%s",Hie.Cty.Name[Gbl.Prefs.Language]);
 		  HTM_BUTTON_End ();
@@ -254,8 +254,8 @@ static void Crs_WriteListMyCoursesToSelectOne (void)
 		  Lay_IndentDependingOnLevel (2,IsLastItemInLevel);
 		  Frm_BeginForm (ActMyCrs);
 		     Ins_PutParamInsCod (Hie.Ins.InsCod);
-		     HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeInsInf),
-					        "BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeInsInf),NULL,
+					        "class=\"BT_LINK\"");
 			Lgo_DrawLogo (HieLvl_INS,Hie.Ins.InsCod,Hie.Ins.ShrtName,16,NULL,true);
 			HTM_TxtF ("&nbsp;%s",Hie.Ins.ShrtName);
 		     HTM_BUTTON_End ();
@@ -287,8 +287,8 @@ static void Crs_WriteListMyCoursesToSelectOne (void)
 		     Lay_IndentDependingOnLevel (3,IsLastItemInLevel);
 		     Frm_BeginForm (ActMyCrs);
 			Ctr_PutParamCtrCod (Hie.Ctr.CtrCod);
-			HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeCtrInf),
-						   "BT_LINK",NULL);
+			HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeCtrInf),NULL,
+						   "class=\"BT_LINK\"");
 			   Lgo_DrawLogo (HieLvl_CTR,Hie.Ctr.CtrCod,Hie.Ctr.ShrtName,16,NULL,true);
 			   HTM_TxtF ("&nbsp;%s",Hie.Ctr.ShrtName);
 			HTM_BUTTON_End ();
@@ -320,8 +320,8 @@ static void Crs_WriteListMyCoursesToSelectOne (void)
 			Lay_IndentDependingOnLevel (4,IsLastItemInLevel);
 			Frm_BeginForm (ActMyCrs);
 			   Deg_PutParamDegCod (Hie.Deg.DegCod);
-			   HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeDegInf),
-						      "BT_LINK",NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (ActSeeDegInf),NULL,
+						      "class=\"BT_LINK\"");
 			      Lgo_DrawLogo (HieLvl_DEG,Hie.Deg.DegCod,Hie.Deg.ShrtName,16,NULL,true);
 			      HTM_TxtF ("&nbsp;%s",Hie.Deg.ShrtName);
 			   HTM_BUTTON_End ();
@@ -353,8 +353,8 @@ static void Crs_WriteListMyCoursesToSelectOne (void)
 			   Lay_IndentDependingOnLevel (5,IsLastItemInLevel);
 			   Frm_BeginForm (ActMyCrs);
 			      Crs_PutParamCrsCod (Hie.Crs.CrsCod);
-			      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Hie.Crs.ShrtName),
-						         "BT_LINK",NULL);
+			      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Hie.Crs.ShrtName),NULL,
+						         "class=\"BT_LINK\"");
 			      Str_FreeGoToTitle ();
 				 Ico_PutIcon ("chalkboard-teacher.svg",Ico_BLACK,Hie.Crs.FullName,"ICO16x16");
 				 HTM_TxtF ("&nbsp;%s",Hie.Crs.ShrtName);
@@ -994,8 +994,8 @@ static bool Crs_ListCoursesOfAYearForSeeing (unsigned Year)
 	                  TxtClassStrong,The_Colors[Gbl.Prefs.Theme],BgColor);
 	       Frm_BeginFormGoTo (ActSeeCrsInf);
 		  Crs_PutParamCrsCod (Crs->CrsCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs->FullName),
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs->FullName),NULL,
+					     "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     HTM_Txt (Crs->FullName);
 		  HTM_BUTTON_End ();
@@ -2470,8 +2470,8 @@ static void Crs_WriteRowCrsData (unsigned NumCrs,MYSQL_ROW row,bool WriteColumnA
                     ClassTxt,The_Colors[Gbl.Prefs.Theme],BgColor);
 	 Frm_BeginFormGoTo (ActSeeDegInf);
 	    Deg_PutParamDegCod (Deg.DegCod);
-	    HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (row[2]),
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (row[2]),NULL,
+	                               "class=\"BT_LINK\"");
             Str_FreeGoToTitle ();
 	       Lgo_DrawLogo (HieLvl_DEG,Deg.DegCod,Deg.ShrtName,20,"CT",true);
 	       HTM_TxtF ("&nbsp;%s&nbsp;(%s)",row[2],row[6]);
@@ -2490,8 +2490,8 @@ static void Crs_WriteRowCrsData (unsigned NumCrs,MYSQL_ROW row,bool WriteColumnA
                     ClassTxt,The_Colors[Gbl.Prefs.Theme],BgColor);
 	 Frm_BeginFormGoTo (ActSeeCrsInf);
 	    Crs_PutParamCrsCod (CrsCod);
-	    HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (row[5]),
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (row[5]),NULL,
+	                               "class=\"BT_LINK\"");
             Str_FreeGoToTitle ();
 	       HTM_Txt (row[5]);
 	    HTM_BUTTON_End ();
diff --git a/swad_course_config.c b/swad_course_config.c
index 118d8c1d..1a6fa18c 100644
--- a/swad_course_config.c
+++ b/swad_course_config.c
@@ -250,8 +250,8 @@ static void CrsCfg_Degree (bool PrintView,bool PutForm)
 	      {
 	       Frm_BeginFormGoTo (ActSeeDegInf);
 		  Deg_PutParamDegCod (Gbl.Hierarchy.Deg.DegCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Deg.ShrtName),
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Deg.ShrtName),NULL,
+					     "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 	      }
 	    Lgo_DrawLogo (HieLvl_DEG,Gbl.Hierarchy.Deg.DegCod,Gbl.Hierarchy.Deg.ShrtName,
@@ -445,7 +445,7 @@ static void CrsCfg_Indicators (void)
 			  IndicatorsCrs.NumIndicators,
 			  Txt_of_PART_OF_A_TOTAL,Ind_NUM_INDICATORS) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	       HTM_TxtF ("%s&nbsp;",Title);
 	       if (IndicatorsCrs.NumIndicators == Ind_NUM_INDICATORS)
 		  Ico_PutIcon ("check-circle.svg",Ico_GREEN,
diff --git a/swad_date.c b/swad_date.c
index 4d39f081..b1bf63fc 100644
--- a/swad_date.c
+++ b/swad_date.c
@@ -339,8 +339,8 @@ void Dat_ShowClientLocalTime (void)
       /* Month with link to calendar */
       HTM_DIV_Begin ("id=\"current_month\"");
 	 Frm_BeginForm (ActSeeCal);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Show_calendar,
-	                               "BT_LINK CURRENT_MONTH",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Show_calendar,NULL,
+	                               "class=\"BT_LINK CURRENT_MONTH\"");
 	       HTM_SPAN_Begin ("id=\"current_month_txt\"");
 	       // JavaScript will write HTML here
 	       HTM_SPAN_End ();
@@ -353,8 +353,8 @@ void Dat_ShowClientLocalTime (void)
 	 if (Gbl.Usrs.Me.Logged)
 	   {
 	    Frm_BeginForm (ActSeeMyAgd);
-	       HTM_BUTTON_OnSubmit_Begin (Txt_Show_agenda,
-	                                  "BT_LINK CURRENT_DAY",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_Show_agenda,NULL,
+	                                  "class=\"BT_LINK CURRENT_DAY\"");
 	   }
 	 HTM_SPAN_Begin ("id=\"current_day_txt\"");
 	 // JavaScript will write HTML here
diff --git a/swad_degree.c b/swad_degree.c
index f6eac403..8d5a0f43 100644
--- a/swad_degree.c
+++ b/swad_degree.c
@@ -194,8 +194,8 @@ void Deg_DrawDegreeLogoAndNameWithLink (struct Deg_Degree *Deg,Act_Action_t Acti
       Deg_PutParamDegCod (Deg->DegCod);
 
       /***** Link to action *****/
-      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Deg->FullName),
-                                 "BT_LINK",NULL);
+      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Deg->FullName),NULL,
+                                 "class=\"BT_LINK\"");
       Str_FreeGoToTitle ();
 
 	 /***** Degree logo and name *****/
diff --git a/swad_degree_config.c b/swad_degree_config.c
index 683babad..26cf6872 100644
--- a/swad_degree_config.c
+++ b/swad_degree_config.c
@@ -244,8 +244,8 @@ static void DegCfg_Center (bool PrintView,bool PutForm)
 	      {
 	       Frm_BeginFormGoTo (ActSeeCtrInf);
 		  Ctr_PutParamCtrCod (Gbl.Hierarchy.Ctr.CtrCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Ctr.ShrtName),
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Ctr.ShrtName),NULL,
+					     "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 	      }
 	    Lgo_DrawLogo (HieLvl_CTR,Gbl.Hierarchy.Ctr.CtrCod,Gbl.Hierarchy.Ctr.ShrtName,
@@ -335,7 +335,7 @@ static void DegCfg_NumCrss (void)
 	    Deg_PutParamDegCod (Gbl.Hierarchy.Deg.DegCod);
 	    if (asprintf (&Title,Txt_Courses_of_DEGREE_X,Gbl.Hierarchy.Deg.ShrtName) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	    free (Title);
 	       HTM_Unsigned (Crs_GetCachedNumCrssInDeg (Gbl.Hierarchy.Deg.DegCod));
 	    HTM_BUTTON_End ();
diff --git a/swad_degree_type.c b/swad_degree_type.c
index 30eb0dbf..03f74881 100644
--- a/swad_degree_type.c
+++ b/swad_degree_type.c
@@ -550,8 +550,8 @@ static void DegTyp_PutHeadDegreeTypesForSeeing (Act_Action_t NextAction,
 	       Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
 
 	       /* Link with the head of this column */
-	       HTM_BUTTON_OnSubmit_Begin (Txt_DEGREE_TYPES_HELP_ORDER[Order],
-	                                  "BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_DEGREE_TYPES_HELP_ORDER[Order],NULL,
+	                                  "class=\"BT_LINK\"");
 		  if (Order == SelectedOrder)
 		     HTM_U_Begin ();
 		  HTM_Txt (Txt_DEGREE_TYPES_ORDER[Order]);
diff --git a/swad_department.c b/swad_department.c
index 0a89709d..d937d507 100644
--- a/swad_department.c
+++ b/swad_department.c
@@ -150,8 +150,8 @@ void Dpt_SeeDepts (void)
 
 	       Frm_BeginForm (ActSeeDpt);
 		  Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_DEPARTMENTS_HELP_ORDER[Order],
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_DEPARTMENTS_HELP_ORDER[Order],NULL,
+		                             "class=\"BT_LINK\"");
 		     if (Order == Departments.SelectedOrder)
 			HTM_U_Begin ();
 		     HTM_Txt (Txt_DEPARTMENTS_ORDER[Order]);
diff --git a/swad_enrolment.c b/swad_enrolment.c
index 50ab5c72..08885f5e 100644
--- a/swad_enrolment.c
+++ b/swad_enrolment.c
@@ -2232,8 +2232,8 @@ static void Enr_ShowEnrolmentRequestsGivenRoles (unsigned RolesSelected)
 
 			Frm_BeginFormGoTo (ActSeeCrsInf);
 			   Crs_PutParamCrsCod (Crs.CrsCod);
-			   HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs.FullName),
-						      "BT_LINK",NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs.FullName),NULL,
+						      "class=\"BT_LINK\"");
 			   Str_FreeGoToTitle ();
 			      HTM_TxtF ("%s &gt; %s",Deg.ShrtName,Crs.ShrtName);
 			   HTM_BUTTON_End ();
diff --git a/swad_exam.c b/swad_exam.c
index 1a0769db..0504d8ce 100644
--- a/swad_exam.c
+++ b/swad_exam.c
@@ -260,8 +260,8 @@ static void Exa_ListAllExams (struct Exa_Exams *Exams)
 		     Frm_BeginForm (ActSeeAllExa);
 			Pag_PutHiddenParamPagNum (Pag_EXAMS,Exams->CurrentPage);
 			Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-			HTM_BUTTON_OnSubmit_Begin (Txt_EXAMS_ORDER_HELP[Order],
-			                           "BT_LINK",NULL);
+			HTM_BUTTON_OnSubmit_Begin (Txt_EXAMS_ORDER_HELP[Order],NULL,
+			                           "class=\"BT_LINK\"");
 			   if (Order == Exams->SelectedOrder)
 			      HTM_U_Begin ();
 			   HTM_Txt (Txt_EXAMS_ORDER[Order]);
@@ -554,7 +554,7 @@ static void Exa_ShowOneExam (struct Exa_Exams *Exams,
       HTM_ARTICLE_Begin (Anchor);
 	 Frm_BeginForm (ActSeeExa);
 	    Exa_PutParams (Exams);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_View_exam,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_View_exam,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Exam->Title);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -587,7 +587,7 @@ static void Exa_ShowOneExam (struct Exa_Exams *Exams,
       Exams->ExaCod = Exam->ExaCod;
       Frm_BeginForm (ActSeeExa);
 	 Exa_PutParams (Exams);
-	 HTM_BUTTON_OnSubmit_Begin (Txt_Sessions,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_Sessions,NULL,"class=\"BT_LINK\"");
 	    if (ShowOnlyThisExam)
 	       HTM_TxtColonNBSP (Txt_Sessions);
 	    HTM_Unsigned (Exam->NumSess);
diff --git a/swad_exam_result.c b/swad_exam_result.c
index 7e67d4f7..1fc83f34 100644
--- a/swad_exam_result.c
+++ b/swad_exam_result.c
@@ -656,9 +656,8 @@ static void ExaRes_ListExamsToSelect (struct Exa_Exams *Exams)
 
 	    /***** Put link to refresh *****/
 	    HTM_DIV_Begin ("class=\"UPD\"");
-	       HTM_BUTTON_OnSubmit_Begin (Txt_Update_results,
-					  The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme],
-					  NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_Update_results,NULL,
+					  "class=\"%s\"",The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme]);
 		  Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Update_results);
 	       HTM_BUTTON_End ();
 	    HTM_DIV_End ();
diff --git a/swad_exam_session.c b/swad_exam_session.c
index 74a486d6..8c1a0cb7 100644
--- a/swad_exam_session.c
+++ b/swad_exam_session.c
@@ -528,7 +528,8 @@ static void ExaSes_ListOneOrMoreSessionsTitleGrps (struct Exa_Exams *Exams,
 	       ExaSes_PutParamSesCod (Session->SesCod);
 	       HTM_BUTTON_OnSubmit_Begin (Gbl.Usrs.Me.Role.Logged == Rol_STD ? Txt_Play :
 									       Txt_Resume,
-					  "BT_LINK",NULL);
+					  NULL,
+					  "class=\"BT_LINK\"");
 		  HTM_Txt (Session->Title);
 	       HTM_BUTTON_End ();
 	    Frm_EndForm ();
diff --git a/swad_follow.c b/swad_follow.c
index 9681e1c4..f52daf91 100644
--- a/swad_follow.c
+++ b/swad_follow.c
@@ -204,7 +204,7 @@ void Fol_SuggestUsrsToFollowMainZoneOnRightColumn (void)
 
 	 /***** Title with link to suggest more users to follow *****/
 	 Frm_BeginForm (ActSeeSocPrf);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Who_to_follow,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Who_to_follow,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Txt_Who_to_follow);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -405,7 +405,7 @@ static void Fol_ShowNumberOfFollowingOrFollowers (const struct UsrData *UsrDat,
 	 /* Form to list users */
 	 Frm_BeginFormAnchor (Action,Fol_FOLLOW_SECTION_ID);
 	    Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
-	    HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	}
       HTM_Unsigned (NumUsrs);
       if (NumUsrs)
@@ -423,7 +423,7 @@ static void Fol_ShowNumberOfFollowingOrFollowers (const struct UsrData *UsrDat,
 	    /* Form to list users */
 	    Frm_BeginFormAnchor (Action,Fol_FOLLOW_SECTION_ID);
 	       Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
-	       HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	   }
 	 HTM_Txt (Title);
 	 if (NumUsrs)
@@ -634,8 +634,8 @@ static void Fol_ShowFollowedOrFollower (struct UsrData *UsrDat)
 	    Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
 	    HTM_DIV_Begin ("class=\"LT FOLLOW_USR_NAME DAT_%s\"",	// Limited width
 	                   The_Colors[Gbl.Prefs.Theme]);
-	       HTM_BUTTON_OnSubmit_Begin (Txt_Another_user_s_profile,
-	                                  "BT_LINK LT",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_Another_user_s_profile,NULL,
+	                                  "class=\"BT_LINK LT\"");
 		  Usr_WriteFirstNameBRSurnames (UsrDat);
 	       HTM_BUTTON_End ();
 	    HTM_DIV_End ();
@@ -696,8 +696,8 @@ static void Fol_WriteRowUsrToFollowOnRightColumn (struct UsrData *UsrDat)
 	    Frm_BeginForm (ActSeeOthPubPrf);
 	       Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
 	       HTM_DIV_Begin ("class=\"CON_NAME_FOLLOW CON_CRS LT\"");	// Limited width
-		  HTM_BUTTON_OnSubmit_Begin (Txt_Another_user_s_profile,
-		                             "BT_LINK LT",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_Another_user_s_profile,NULL,
+		                             "class=\"BT_LINK LT\"");
 		     Usr_WriteFirstNameBRSurnames (UsrDat);
 		  HTM_BUTTON_End ();
 	       HTM_DIV_End ();
diff --git a/swad_forum.c b/swad_forum.c
index 1c1de4db..d6fa09dd 100644
--- a/swad_forum.c
+++ b/swad_forum.c
@@ -1694,19 +1694,15 @@ static void For_WriteLinkToForum (const struct For_Forums *Forums,
                                   unsigned Level,
                                   bool IsLastItemInLevel[1 + For_FORUM_MAX_LEVELS])
   {
-   extern const char *The_ClassFormLinkInBox[The_NUM_THEMES];
-   extern const char *The_ClassFormLinkInBoxBold[The_NUM_THEMES];
+   extern const char *The_Colors[The_NUM_THEMES];
    extern const char *Txt_Copy_not_allowed;
    unsigned NumThrs;
    unsigned NumThrsWithNewPosts;
-   const char *Class;
    char ForumName[For_MAX_BYTES_FORUM_NAME + 1];
 
    /***** Get number of threads and number of posts *****/
    NumThrs = For_DB_GetNumThrsInForum (Forum);
    NumThrsWithNewPosts = For_GetNumThrsWithNewPstsInForum (Forum,NumThrs);
-   Class = (NumThrsWithNewPosts ? The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme] :
-	                          The_ClassFormLinkInBox[Gbl.Prefs.Theme]);
 
    /***** Begin row *****/
    HTM_LI_Begin (Highlight ? "class=\"BG_HIGHLIGHT\"" :
@@ -1749,8 +1745,10 @@ static void For_WriteLinkToForum (const struct For_Forums *Forums,
 				      -1L,
 				      -1L);
 
-	 HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (For_ActionsSeeFor[Forum->Type]),
-				    Class,NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Act_GetActionText (For_ActionsSeeFor[Forum->Type]),NULL,
+				    NumThrsWithNewPosts ? "class=\"BT_LINK FORM_IN_%s BOLD\"" :
+	                                                  "class=\"BT_LINK FORM_IN_%s\"",
+	                            The_Colors[Gbl.Prefs.Theme]);
 
 	    For_SetForumName (Forum,ForumName,Gbl.Prefs.Language,true);
 	    switch (Forum->Type)
@@ -2082,8 +2080,8 @@ static void For_ShowForumThreadsHighlightingOneThread (struct For_Forums *Forums
 							Forums->Forum.Location,
 							-1L,
 							-1L);
-			   HTM_BUTTON_OnSubmit_Begin (Txt_FORUM_THREAD_HELP_ORDER[Order],
-			                              "BT_LINK",NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Txt_FORUM_THREAD_HELP_ORDER[Order],NULL,
+			                              "BT_LINK");
 			      if (Order == Forums->ThreadsOrder)
 				 HTM_U_Begin ();
 			      HTM_Txt (Txt_FORUM_THREAD_ORDER[Order]);
diff --git a/swad_game.c b/swad_game.c
index bfc826bb..62ac326f 100644
--- a/swad_game.c
+++ b/swad_game.c
@@ -283,8 +283,8 @@ static void Gam_ListAllGames (struct Gam_Games *Games)
 			Pag_PutHiddenParamPagNum (Pag_GAMES,Games->CurrentPage);
 			Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
 
-			HTM_BUTTON_OnSubmit_Begin (Txt_GAMES_ORDER_HELP[Order],
-			                           "BT_LINK",NULL);
+			HTM_BUTTON_OnSubmit_Begin (Txt_GAMES_ORDER_HELP[Order],NULL,
+			                           "class=\"BT_LINK\"");
 			   if (Order == Games->SelectedOrder)
 			      HTM_U_Begin ();
 			   HTM_Txt (Txt_GAMES_ORDER[Order]);
@@ -605,7 +605,7 @@ static void Gam_ShowOneGame (struct Gam_Games *Games,
       HTM_ARTICLE_Begin (Anchor);
 	 Frm_BeginForm (ActSeeGam);
 	    Gam_PutParams (Games);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_View_game,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_View_game,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Game->Title);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -638,7 +638,7 @@ static void Gam_ShowOneGame (struct Gam_Games *Games,
       Games->GamCod = Game->GamCod;
       Frm_BeginForm (ActSeeGam);
 	 Gam_PutParams (Games);
-	 HTM_BUTTON_OnSubmit_Begin (Txt_Matches,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_Matches,NULL,"class=\"BT_LINK\"");
 	    if (ShowOnlyThisGame)
 	       HTM_TxtColonNBSP (Txt_Matches);
 	    HTM_Unsigned (Game->NumMchs);
diff --git a/swad_group.c b/swad_group.c
index 94fc0fc7..5e3e9523 100644
--- a/swad_group.c
+++ b/swad_group.c
@@ -410,9 +410,9 @@ void Grp_ShowFormToSelectSeveralGroups (void (*FuncParams) (void *Args),void *Ar
       /***** Submit button *****/
       HTM_DIV_Begin ("class=\"UPD\"");
 	 HTM_BUTTON_OnSubmit_Begin (Txt_Update_users,
-				    The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme],
 				    Gbl.Action.Act == ActReqMsgUsr ? "CopyMessageToHiddenFields();" :
-								     NULL);
+								     NULL,
+				    "class=\"%s\"",The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme]);
 	    Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Update_users);
 	 HTM_BUTTON_End ();
       HTM_DIV_End ();
diff --git a/swad_hierarchy.c b/swad_hierarchy.c
index 5fb17c17..a1b74049 100644
--- a/swad_hierarchy.c
+++ b/swad_hierarchy.c
@@ -210,7 +210,7 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 
       Frm_BeginFormGoTo (ActMnu);
 	 Par_PutHiddenParamUnsigned (NULL,"NxtTab",(unsigned) TabSys);
-	 HTM_BUTTON_OnSubmit_Begin (Txt_System,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_System,NULL,"class=\"BT_LINK\"");
 	    HTM_Txt (Txt_System);
 	 HTM_BUTTON_End ();
       Frm_EndForm ();
@@ -227,8 +227,8 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 	 /***** Form to go to see institutions of this country *****/
 	 Frm_BeginFormGoTo (ActSeeIns);
 	    Cty_PutParamCtyCod (Gbl.Hierarchy.Cty.CtyCod);
-	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Cty.Name[Gbl.Prefs.Language],
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Cty.Name[Gbl.Prefs.Language],NULL,
+	                               "class=\"BT_LINK\"");
 	       HTM_Txt (Gbl.Hierarchy.Cty.Name[Gbl.Prefs.Language]);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -244,7 +244,7 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 
 	 /***** Form to go to select countries *****/
 	 Frm_BeginFormGoTo (ActSeeCty);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Country,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Country,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Txt_Country);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -262,8 +262,8 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 	 /***** Form to see centers of this institution *****/
 	 Frm_BeginFormGoTo (ActSeeCtr);
 	    Ins_PutParamInsCod (Gbl.Hierarchy.Ins.InsCod);
-	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Ins.FullName,
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Ins.FullName,NULL,
+	                               "class=\"BT_LINK\"");
 	       HTM_Txt (Gbl.Hierarchy.Ins.ShrtName);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -279,7 +279,7 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 
 	 /***** Form to go to select institutions *****/
 	 Frm_BeginFormGoTo (ActSeeIns);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Institution,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Institution,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Txt_Institution);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -309,8 +309,8 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 	 /***** Form to see degrees of this center *****/
 	 Frm_BeginFormGoTo (ActSeeDeg);
 	    Ctr_PutParamCtrCod (Gbl.Hierarchy.Ctr.CtrCod);
-	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Ctr.FullName,
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Ctr.FullName,NULL,
+	                               "class=\"BT_LINK\"");
 	       HTM_Txt (Gbl.Hierarchy.Ctr.ShrtName);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -326,7 +326,7 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 
 	 /***** Form to go to select centers *****/
 	 Frm_BeginFormGoTo (ActSeeCtr);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Center,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Center,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Txt_Center);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -356,8 +356,8 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 	 /***** Form to go to see courses of this degree *****/
 	 Frm_BeginFormGoTo (ActSeeCrs);
 	    Deg_PutParamDegCod (Gbl.Hierarchy.Deg.DegCod);
-	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Deg.FullName,
-	                               "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Gbl.Hierarchy.Deg.FullName,NULL,
+	                               "class=\"BT_LINK\"");
 	       HTM_Txt (Gbl.Hierarchy.Deg.ShrtName);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -373,7 +373,7 @@ void Hie_WriteHierarchyInBreadcrumb (void)
 
 	 /***** Form to go to select degrees *****/
 	 Frm_BeginFormGoTo (ActSeeDeg);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Degree,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Degree,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Txt_Degree);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
diff --git a/swad_hierarchy_config.c b/swad_hierarchy_config.c
index 387d82c7..5c7ecabe 100644
--- a/swad_hierarchy_config.c
+++ b/swad_hierarchy_config.c
@@ -273,7 +273,7 @@ void HieCfg_NumCtrs (unsigned NumCtrs,bool PutForm)
 	       if (asprintf (&Title,Txt_Centers_of_INSTITUTION_X,
 	                     Gbl.Hierarchy.Ins.ShrtName) < 0)
 		  Err_NotEnoughMemoryExit ();
-	       HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 	       free (Title);
 	   }
 	 HTM_Unsigned (NumCtrs);
diff --git a/swad_holiday.c b/swad_holiday.c
index 663d291b..2ffa1f20 100644
--- a/swad_holiday.c
+++ b/swad_holiday.c
@@ -137,8 +137,8 @@ void Hld_SeeHolidays (void)
                      HTM_TH_Begin (HTM_HEAD_LEFT);
 			Frm_BeginForm (ActSeeHld);
 			   Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-			   HTM_BUTTON_OnSubmit_Begin (Txt_HOLIDAYS_HELP_ORDER[Order],
-			                              "BT_LINK",NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Txt_HOLIDAYS_HELP_ORDER[Order],NULL,
+			                              "class=\"BT_LINK\"");
 			      if (Order == Holidays.SelectedOrder)
 				 HTM_U_Begin ();
 			      HTM_Txt (Txt_HOLIDAYS_ORDER[Order]);
diff --git a/swad_info.c b/swad_info.c
index 78578ecf..96d718fb 100644
--- a/swad_info.c
+++ b/swad_info.c
@@ -516,7 +516,7 @@ bool Inf_GetIfIMustReadAnyCrsInfoInThisCrs (void)
 
 void Inf_WriteMsgYouMustReadInfo (void)
   {
-   extern const char *The_ClassFormLinkInBox[The_NUM_THEMES];
+   extern const char *The_Colors[The_NUM_THEMES];
    extern const char *Txt_Required_reading;
    extern const char *Txt_You_should_read_the_following_information;
    Inf_Type_t InfoType;
@@ -539,8 +539,9 @@ void Inf_WriteMsgYouMustReadInfo (void)
 		 {
 		  HTM_LI_Begin (NULL);
 		     Frm_BeginForm (Inf_ActionsSeeInfo[InfoType]);
-			HTM_BUTTON_OnSubmit_Begin (Act_GetTitleAction (Inf_ActionsSeeInfo[InfoType]),
-						   The_ClassFormLinkInBox[Gbl.Prefs.Theme],NULL);
+			HTM_BUTTON_OnSubmit_Begin (Act_GetTitleAction (Inf_ActionsSeeInfo[InfoType]),NULL,
+						   "class=\"BT_LINK FORM_IN_%s\"",
+						   The_Colors[Gbl.Prefs.Theme]);
 			   HTM_Txt (Act_GetTitleAction (Inf_ActionsSeeInfo[InfoType]));
 			HTM_BUTTON_End ();
 		     Frm_EndForm ();
diff --git a/swad_institution.c b/swad_institution.c
index 5aefd0f8..4135290e 100644
--- a/swad_institution.c
+++ b/swad_institution.c
@@ -213,7 +213,7 @@ void Ins_DrawInstitutionLogoWithLink (struct Ins_Instit *Ins,unsigned Size)
      {
       Frm_BeginForm (ActSeeInsInf);
 	 Ins_PutParamInsCod (Ins->InsCod);
-	 HTM_BUTTON_OnSubmit_Begin (Ins->FullName,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Ins->FullName,NULL,"class=\"BT_LINK\"");
      }
    Lgo_DrawLogo (HieLvl_INS,Ins->InsCod,Ins->FullName,
 		 Size,NULL,true);
@@ -236,8 +236,8 @@ void Ins_DrawInstitLogoAndNameWithLink (struct Ins_Instit *Ins,Act_Action_t Acti
       Ins_PutParamInsCod (Ins->InsCod);
 
       /***** Link to action *****/
-      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Ins->FullName),
-                                 "BT_LINK LT",NULL);
+      HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Ins->FullName),NULL,
+                                 "class=\"BT_LINK LT\"");
       Str_FreeGoToTitle ();
 
 	 /***** Institution logo and name *****/
@@ -484,8 +484,8 @@ static void Ins_PutHeadInstitutionsForSeeing (bool OrderSelectable)
 	      {
 	       Frm_BeginForm (ActSeeIns);
 		  Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_INSTITUTIONS_HELP_ORDER[Order],
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_INSTITUTIONS_HELP_ORDER[Order],NULL,
+		                             "class=\"BT_LINK\"");
 		     if (Order == Gbl.Hierarchy.Inss.SelectedOrder)
 			HTM_U_Begin ();
 	      }
@@ -2352,7 +2352,7 @@ static void Ins_ShowInss (MYSQL_RES **mysql_res,unsigned NumInss,
 		     /* Icon and name of this institution */
 		     Frm_BeginForm (ActSeeInsInf);
 			Ins_PutParamInsCod (Ins.InsCod);
-			HTM_BUTTON_OnSubmit_Begin (Ins.ShrtName,"BT_LINK",NULL);
+			HTM_BUTTON_OnSubmit_Begin (Ins.ShrtName,NULL,"class=\"BT_LINK\"");
 			   if (Gbl.Usrs.Listing.WithPhotos)
 			     {
 			      Lgo_DrawLogo (HieLvl_INS,Ins.InsCod,Ins.ShrtName,
diff --git a/swad_institution_config.c b/swad_institution_config.c
index 7563dcd4..885b56a8 100644
--- a/swad_institution_config.c
+++ b/swad_institution_config.c
@@ -342,8 +342,8 @@ static void InsCfg_Country (bool PrintView,bool PutForm)
 	      {
 	       Frm_BeginFormGoTo (ActSeeCtyInf);
 		  Cty_PutParamCtyCod (Gbl.Hierarchy.Cty.CtyCod);
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Cty.Name[Gbl.Prefs.Language]),
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Gbl.Hierarchy.Cty.Name[Gbl.Prefs.Language]),NULL,
+					     "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 	      }
 	    Cty_DrawCountryMap (&Gbl.Hierarchy.Cty,"COUNTRY_MAP_TINY");
diff --git a/swad_layout.c b/swad_layout.c
index 2a2a7701..9a51493a 100644
--- a/swad_layout.c
+++ b/swad_layout.c
@@ -1019,7 +1019,7 @@ static void Lay_WritePageTopHeading (void)
 
 	       HTM_DIV_Begin ("id=\"head_row_1_tagline\" class=\"TAGLINE_%s\"",
 	                      The_Colors[Gbl.Prefs.Theme]);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_TAGLINE,"BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_TAGLINE,NULL,"class=\"BT_LINK\"");
 		     HTM_Txt (Txt_TAGLINE_BR);
 		  HTM_BUTTON_End ();
 	       HTM_DIV_End ();	// head_row_1_tagline
@@ -1230,9 +1230,8 @@ void Lay_PutContextualLinkIconText (Act_Action_t NextAction,const char *Anchor,
 	 FuncParams (Args);
 
       /***** Put icon and text with link *****/
-      HTM_BUTTON_OnSubmit_Begin (Text,
-                                 The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme],
-                                 OnSubmit);
+      HTM_BUTTON_OnSubmit_Begin (Text,OnSubmit,
+                                 "class=\"%s\"",The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme]);
 	 Ico_PutIconTextLink (Icon,Color,Text);
       HTM_BUTTON_End ();
 
diff --git a/swad_link.c b/swad_link.c
index 0f6fe3b7..97f6e20c 100644
--- a/swad_link.c
+++ b/swad_link.c
@@ -161,7 +161,7 @@ void Lnk_WriteMenuWithInstitutionalLinks (void)
                      The_Colors[Gbl.Prefs.Theme]);
 
 	 Frm_BeginForm (ActSeeLnk);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Links,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Links,NULL,"class=\"BT_LINK\"");
 	       HTM_TxtF ("%s",Txt_Links);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
diff --git a/swad_mail.c b/swad_mail.c
index 203262d9..6b21f66f 100644
--- a/swad_mail.c
+++ b/swad_mail.c
@@ -136,8 +136,8 @@ void Mai_SeeMailDomains (void)
 
 	    Frm_BeginForm (ActSeeMai);
 	       Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-	       HTM_BUTTON_OnSubmit_Begin (Txt_EMAIL_DOMAIN_HELP_ORDER[Order],
-	                                  "BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_EMAIL_DOMAIN_HELP_ORDER[Order],NULL,
+	                                  "class=\"BT_LINK\"");
 		  if (Order == Gbl.Mails.SelectedOrder)
 		     HTM_U_Begin ();
 		  HTM_Txt (Txt_EMAIL_DOMAIN_ORDER[Order]);
diff --git a/swad_match.c b/swad_match.c
index 67bd5dd8..1924c829 100644
--- a/swad_match.c
+++ b/swad_match.c
@@ -639,7 +639,8 @@ static void Mch_ListOneOrMoreMatchesTitleGrps (const struct Mch_Match *Match,
 
 	    HTM_BUTTON_OnSubmit_Begin (Gbl.Usrs.Me.Role.Logged == Rol_STD ? Txt_Play :
 									    Txt_Resume,
-				       "BT_LINK LT ASG_TITLE",NULL);
+				       NULL,
+				       "class=\"BT_LINK LT ASG_TITLE\"");
 	       HTM_Txt (Match->Title);
 	    HTM_BUTTON_End ();
 
@@ -2386,9 +2387,9 @@ static void Mch_PutFormCountdown (struct Mch_Match *Match,long Seconds,const cha
 
 	 HTM_BUTTON_OnSubmit_Begin (PutForm ? Txt_Countdown :
 					      NULL,
-				    PutForm ? "BT_LINK MCH_BUTTON_ON" :
-					      "BT_LINK_OFF MCH_BUTTON_HIDDEN",
-				    NULL);
+				    NULL,
+				    PutForm ? "class=\"BT_LINK MCH_BUTTON_ON\"" :
+					      "class=\"BT_LINK_OFF MCH_BUTTON_HIDDEN\"");
 
 	    HTM_NBSP ();
 	    if (Seconds >= 0)
@@ -2699,8 +2700,8 @@ static void Mch_PutCheckboxResult (const struct Mch_Match *Match)
 	 Mch_PutParamMchCod (Match->MchCod);	// Current match being played
 
 	 /***** Put icon with link *****/
-	 HTM_BUTTON_OnSubmit_Begin (Txt_View_results,
-	                            "BT_LINK ICO_HIGHLIGHT",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt_View_results,NULL,
+	                            "class=\"BT_LINK ICO_HIGHLIGHT\"");
 	    HTM_TxtF ("<i class=\"%s\"></i>",
 		      Match->Status.ShowQstResults ? "fas fa-toggle-on" :
 						     "fas fa-toggle-off");
@@ -3308,7 +3309,8 @@ static void Mch_PutBigButton (Act_Action_t NextAction,const char *Id,
 
       /***** Put icon with link *****/
       HTM_DIV_Begin ("class=\"MCH_BIGBUTTON_CONT\"");
-	 HTM_BUTTON_OnSubmit_Begin (Txt,"BT_LINK MCH_BUTTON_ON ICO_BLACK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Txt,NULL,
+	                            "class=\"BT_LINK MCH_BUTTON_ON ICO_BLACK\"");
 	    HTM_TxtF ("<i class=\"%s\"></i>",Icon);
 	 HTM_BUTTON_End ();
       HTM_DIV_End ();
diff --git a/swad_match_result.c b/swad_match_result.c
index dec7eb28..ca1da708 100644
--- a/swad_match_result.c
+++ b/swad_match_result.c
@@ -612,9 +612,8 @@ static void MchRes_ListGamesToSelect (struct Gam_Games *Games)
 
 	 /***** Put button to refresh *****/
 	 HTM_DIV_Begin ("class=\"UPD\"");
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Update_results,
-				       The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme],
-				       NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Update_results,NULL,
+				       "class=\"%s\"",The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme]);
 	       Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Update_results);
 	    HTM_BUTTON_End ();
 	 HTM_DIV_End ();
diff --git a/swad_menu.c b/swad_menu.c
index 9a9350c8..3a93daae 100644
--- a/swad_menu.c
+++ b/swad_menu.c
@@ -268,7 +268,7 @@ void Mnu_WriteMenuThisTab (void)
 		  Frm_BeginForm (NumAct);
 
 		     /***** Begin link *****/
-		     HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Title,NULL,"class=\"BT_LINK\"");
 
 			/***** Icon and text *****/
 			HTM_DIV_Begin ("class=\"MENU_ICO_TXT\"");
diff --git a/swad_message.c b/swad_message.c
index a013751e..1953bcb6 100644
--- a/swad_message.c
+++ b/swad_message.c
@@ -1526,8 +1526,8 @@ static void Msg_ShowSntOrRcvMessages (struct Msg_Messages *Messages)
 	    /***** Put button to refresh *****/
 	    HTM_DIV_Begin ("class=\"UPD\"");
 	       HTM_BUTTON_OnSubmit_Begin (Txt_Update_messages,
-					  The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme],
-					  NULL);
+					  NULL,
+					  "class=\"%s\"",The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme]);
 		  Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Update_messages);
 	       HTM_BUTTON_End ();
 	    HTM_DIV_End ();
@@ -2288,7 +2288,8 @@ static void Msg_WriteSentOrReceivedMsgSubject (struct Msg_Messages *Messages,
 
 	 HTM_BUTTON_OnSubmit_Begin (Expanded ? Txt_Hide_message :
 					       Txt_See_message,
-				    "BT_LINK",NULL);
+				    NULL,
+				    "class=\"BT_LINK\"");
 
 	    /***** Write subject *****/
 	    if (Subject[0])
@@ -2412,8 +2413,8 @@ static bool Msg_WriteCrsOrgMsg (long CrsCod)
 	       Crs_PutParamCrsCod (Crs.CrsCod);
 	       HTM_DIV_Begin ("class=\"AUTHOR_TXT\"");
 		  HTM_Txt ("(");
-		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs.FullName),
-					     "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs.FullName),NULL,
+					     "class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     HTM_Txt (Crs.ShrtName);
 		  HTM_BUTTON_End ();
@@ -2690,8 +2691,8 @@ static void Msg_WriteMsgTo (struct Msg_Messages *Messages,long MsgCod)
 		     Messages->MsgCod = MsgCod;	// Message to be expanded with all recipients visible
 		     Msg_PutHiddenParamsOneMsg (Messages);
 		     Par_PutHiddenParamChar ("SeeAllRcpts",'Y');
-			HTM_BUTTON_OnSubmit_Begin (Txt_View_all_recipients,
-			                           "BT_LINK",NULL);
+			HTM_BUTTON_OnSubmit_Begin (Txt_View_all_recipients,NULL,
+			                           "class=\"BT_LINK\"");
 			   HTM_TxtF (Txt_and_X_other_recipients,
 				     NumRecipients.Known - NumRecipients.ToShow);
 			HTM_BUTTON_End ();
diff --git a/swad_notice.c b/swad_notice.c
index b8b68299..a53d97f8 100644
--- a/swad_notice.c
+++ b/swad_notice.c
@@ -612,7 +612,8 @@ static void Not_DrawANotice (Not_Listing_t TypeNoticesListing,
 	    /* Form to view full notice */
 	    Frm_BeginFormAnchor (ActSeeOneNot,Anchor);
 	       Not_PutHiddenParamNotCod (NotCod);
-	       HTM_BUTTON_OnSubmit_Begin (Txt_See_full_notice,"BT_LINK RT",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Txt_See_full_notice,NULL,
+	                                  "class=\"RT BT_LINK\"");
 	   }
 	 if (asprintf (&Id,"not_date_%u",UniqueId) < 0)
 	    Err_NotEnoughMemoryExit ();
diff --git a/swad_notification.c b/swad_notification.c
index 41a820ac..ad5e8ef6 100644
--- a/swad_notification.c
+++ b/swad_notification.c
@@ -503,8 +503,8 @@ void Ntf_ShowMyNotifications (void)
 		     if (PutLink)
 		       {
 			PutLink = Ntf_StartFormGoToAction (NotifyEvent,Hie.Crs.CrsCod,&UsrDat,Cod,&Forums);
-			   HTM_BUTTON_OnSubmit_Begin (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent],
-			                              ClassLink,NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent],NULL,
+			                              "class=\"%s\"",ClassLink);
 			      HTM_Txt (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent]);
 			   HTM_BUTTON_End ();
 			Frm_EndForm ();
@@ -532,8 +532,8 @@ void Ntf_ShowMyNotifications (void)
 			   PutLink = Ntf_StartFormGoToAction (NotifyEvent,Hie.Crs.CrsCod,&UsrDat,Cod,&Forums);
 
 			if (PutLink)
-			   HTM_BUTTON_OnSubmit_Begin (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent],
-			                              ClassLink,NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent],NULL,
+			                              "class=\"%s\"",ClassLink);
 			else
 			   HTM_SPAN_Begin ("class=\"%s\"",ClassText);
 			HTM_TxtF ("%s:&nbsp;%s",Txt_Forum,ForumName);
@@ -551,8 +551,8 @@ void Ntf_ShowMyNotifications (void)
 			   PutLink = Ntf_StartFormGoToAction (NotifyEvent,Hie.Crs.CrsCod,&UsrDat,Cod,&Forums);
 
 			if (PutLink)
-			   HTM_BUTTON_OnSubmit_Begin (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent],
-			                              ClassLink,NULL);
+			   HTM_BUTTON_OnSubmit_Begin (Txt_NOTIFY_EVENTS_SINGULAR[NotifyEvent],NULL,
+			                              "class=\"%s\"",ClassLink);
 			else
 			   HTM_SPAN_Begin ("class=\"%s\"",ClassText);
 
@@ -1650,7 +1650,7 @@ void Ntf_WriteNumberOfNewNtfs (void)
    Frm_BeginFormId (ActSeeNewNtf,"form_ntf");
 
       /***** Begin link *****/
-      HTM_BUTTON_OnSubmit_Begin (Txt_See_notifications,"BT_LINK",NULL);
+      HTM_BUTTON_OnSubmit_Begin (Txt_See_notifications,NULL,"class=\"BT_LINK\"");
 
 	 /***** Number of unseen notifications *****/
 	 HTM_SPAN_Begin ("id=\"notif_all\"");
diff --git a/swad_pagination.c b/swad_pagination.c
index 239ba98e..2c6b9887 100644
--- a/swad_pagination.c
+++ b/swad_pagination.c
@@ -164,7 +164,6 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
    extern const char *Txt_FORUM_Post_banned;
    Grp_WhichGroups_t WhichGroups;
    unsigned NumPage;
-   char *ClassLink;
    char *Title;
 
    /***** Link to page 1, including a text *****/
@@ -267,14 +266,12 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
 	       default:
 		  break;
 	      }
-	    if (asprintf (&ClassLink,"BT_LINK LT %s_%s",
-	                  ClassTxt,The_Colors[Gbl.Prefs.Theme]) < 0)
-	       Err_NotEnoughMemoryExit ();
 	    if (asprintf (&Title,Txt_Page_X_of_Y,1,Pagination->NumPags) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,ClassLink,NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+	                               "class=\"LT BT_LINK %s_%s\"",
+	                               ClassTxt,The_Colors[Gbl.Prefs.Theme]);
 	    free (Title);
-	    free (ClassLink);
 	   }
 	 else
 	    HTM_SPAN_Begin ("class=\"%s\"",ClassTxt);
@@ -295,9 +292,6 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
    /***** Links to several pages start here *****/
    if (Pagination->MoreThanOnePage)
      {
-      if (asprintf (&ClassLink,"BT_LINK PAG %s",ClassTxt) < 0)
-	 Err_NotEnoughMemoryExit ();
-
       /***** Possible link to page 1 *****/
       if (Pagination->StartPage > 1)
         {
@@ -397,7 +391,8 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
            }
 	    if (asprintf (&Title,Txt_Page_X_of_Y,1,Pagination->NumPags) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,ClassLink,NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+	                               "class=\"BT_LINK PAG %s\"",ClassTxt);
 	       HTM_Unsigned (1);
 	    HTM_BUTTON_End ();
 	    free (Title);
@@ -511,7 +506,8 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
 	    if (asprintf (&Title,Txt_Page_X_of_Y,
 			  Pagination->LeftPage,Pagination->NumPags) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,ClassLink,NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+	                               "class=\"BT_LINK PAG %s\"",ClassTxt);
 	       HTM_Unsigned (Pagination->LeftPage);
 	    HTM_BUTTON_End ();
 	    free (Title);
@@ -633,7 +629,8 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
 	       default:
 		  break;
               }
-	       HTM_BUTTON_OnSubmit_Begin (Title,ClassLink,NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+	                                  "class=\"BT_LINK PAG %s\"",ClassTxt);
 		  HTM_Unsigned (NumPage);
 	       HTM_BUTTON_End ();
             Frm_EndForm ();
@@ -748,7 +745,8 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
 	    if (asprintf (&Title,Txt_Page_X_of_Y,
 			  Pagination->RightPage,Pagination->NumPags) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,ClassLink,NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+	                               "class=\"BT_LINK PAG %s\"",ClassTxt);
 	       HTM_Unsigned (Pagination->RightPage);
 	    HTM_BUTTON_End ();
 	    free (Title);
@@ -861,14 +859,13 @@ void Pag_WriteLinksToPages (Pag_WhatPaginate_t WhatPaginate,
 	    if (asprintf (&Title,Txt_Page_X_of_Y,
 			  Pagination->NumPags,Pagination->NumPags) < 0)
 	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Title,ClassLink,NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+	                               "class=\"BT_LINK PAG %s\"",ClassTxt);
 	       HTM_Unsigned (Pagination->NumPags);
 	    HTM_BUTTON_End ();
 	    free (Title);
          Frm_EndForm ();
         }
-
-      free (ClassLink);
      }
   }
 
diff --git a/swad_photo.c b/swad_photo.c
index 9e67ed18..efcdf528 100644
--- a/swad_photo.c
+++ b/swad_photo.c
@@ -1291,7 +1291,7 @@ void Pho_ShowUsrPhoto (const struct UsrData *UsrDat,const char *PhotoURL,
       else
 	 Frm_BeginForm (ActSeeOthPubPrf);
       Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
-	 HTM_BUTTON_OnSubmit_Begin (NULL,"BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (NULL,NULL,"class=\"BT_LINK\"");
      }
 
    /***** Hidden div to pass user's name to Javascript *****/
@@ -2031,8 +2031,8 @@ static void Pho_PutLinkToCalculateDegreeStats (const struct Pho_DegPhotos *DegPh
 
 	    /***** Put button to refresh *****/
 	    HTM_BUTTON_OnSubmit_Begin (Txt_Calculate_average_photo_of_THE_DEGREE_X,
-				       The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme],
-				       NULL);
+				       NULL,
+				       "class=\"%s\"",The_ClassFormLinkInBoxBold[Gbl.Prefs.Theme]);
 	       Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Calculate_average_photo_of_THE_DEGREE_X);
 	    HTM_BUTTON_End ();
 
@@ -2391,8 +2391,8 @@ static void Pho_ShowDegreeAvgPhotoAndStat (const struct Deg_Degree *Deg,
      {
       Frm_BeginFormGoTo (ActSeeDegInf);
 	 Deg_PutParamDegCod (Deg->DegCod);
-	 HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Deg->FullName),
-	                            "BT_LINK",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Deg->FullName),NULL,
+	                            "class=\"BT_LINK\"");
 	 Str_FreeGoToTitle ();
      }
 
diff --git a/swad_place.c b/swad_place.c
index 5fd20473..33daeea0 100644
--- a/swad_place.c
+++ b/swad_place.c
@@ -132,8 +132,8 @@ void Plc_SeePlaces (void)
 
 		  Frm_BeginForm (ActSeePlc);
 		     Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		     HTM_BUTTON_OnSubmit_Begin (Txt_PLACES_HELP_ORDER[Order],
-		                                "BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Txt_PLACES_HELP_ORDER[Order],NULL,
+		                                "class=\"BT_LINK\"");
 			if (Order == Places.SelectedOrder)
 			   HTM_U_Begin ();
 			HTM_Txt (Txt_PLACES_ORDER[Order]);
diff --git a/swad_profile.c b/swad_profile.c
index 4de03537..ef387334 100644
--- a/swad_profile.c
+++ b/swad_profile.c
@@ -783,8 +783,8 @@ static void Prf_PutLinkCalculateFigures (const char *EncryptedUsrCod)
 
       /***** Put button to refresh *****/
       HTM_BUTTON_OnSubmit_Begin (Txt_Calculate,
-				 The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme],
-				 NULL);
+				 NULL,
+				 "class=\"%s\"",The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme]);
 	 Ico_PutIconTextLink ("recycle.svg",Ico_BLACK,Txt_Calculate);
       HTM_BUTTON_End ();
 
@@ -852,7 +852,7 @@ void Prf_GetUsrFigures (long UsrCod,struct Prf_UsrFigures *UsrFigures)
 
 static void Prf_ShowRanking (unsigned Rank,unsigned NumUsrs)
   {
-   extern const char *The_ClassFormLinkOutBox[The_NUM_THEMES];
+   extern const char *The_Colors[The_NUM_THEMES];
    extern const char *Txt_of_PART_OF_A_TOTAL;
    char *Title;
 
@@ -863,8 +863,9 @@ static void Prf_ShowRanking (unsigned Rank,unsigned NumUsrs)
       if (asprintf (&Title,"#%u %s %u",
 		    Rank,Txt_of_PART_OF_A_TOTAL,NumUsrs) < 0)
 	 Err_NotEnoughMemoryExit ();
-      HTM_BUTTON_OnSubmit_Begin (Title,The_ClassFormLinkOutBox[Gbl.Prefs.Theme],
-                                 NULL);
+      HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+                                 "class=\"BT_LINK FORM_OUT_%s\"",
+                                 The_Colors[Gbl.Prefs.Theme]);
       free (Title);
 	 HTM_TxtF ("#%u",Rank);
       HTM_BUTTON_End ();
@@ -1349,8 +1350,8 @@ static void Prf_ShowUsrInRanking (struct UsrData *UsrDat,unsigned Rank,bool ItsM
 	{
 	 Frm_BeginForm (ActSeeOthPubPrf);
 	    Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Another_user_s_profile,
-				       "BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Another_user_s_profile,NULL,
+				       "class=\"BT_LINK\"");
 	       Usr_WriteFirstNameBRSurnames (UsrDat);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
diff --git a/swad_project.c b/swad_project.c
index ddbafaa0..76faf3e0 100644
--- a/swad_project.c
+++ b/swad_project.c
@@ -1009,8 +1009,8 @@ static void Prj_ShowProjectsHead (struct Prj_Projects *Projects,
 				    Order,
 				    Projects->CurrentPage,
 				    -1L);
-		     HTM_BUTTON_OnSubmit_Begin (Txt_PROJECT_ORDER_HELP[Order],
-		                                "BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Txt_PROJECT_ORDER_HELP[Order],NULL,
+		                                "class=\"BT_LINK\"");
 			if (Order == Projects->SelectedOrder)
 			   HTM_U_Begin ();
 			HTM_Txt (Txt_PROJECT_ORDER[Order]);
@@ -1383,8 +1383,8 @@ static void Prj_ShowOneProject (struct Prj_Projects *Projects,
 		 {
 		  Frm_BeginForm (ActAdmDocPrj);
 		     Prj_PutCurrentParams (Projects);
-		     HTM_BUTTON_OnSubmit_Begin (Txt_Project_files,
-		                                "BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Txt_Project_files,NULL,
+		                                "class=\"BT_LINK\"");
 			HTM_Txt (Prj->Title);
 		     HTM_BUTTON_End ();
 		  Frm_EndForm ();
diff --git a/swad_question.c b/swad_question.c
index 24f90976..545bd2bc 100644
--- a/swad_question.c
+++ b/swad_question.c
@@ -944,8 +944,8 @@ void Qst_WriteHeadingRowQuestionsForEdition (struct Qst_Questions *Questions)
 	       Frm_BeginForm (ActLstTstQst);
 		  Qst_PutParamsEditQst (Questions);
 		  Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_TST_STR_ORDER_FULL[Order],
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_TST_STR_ORDER_FULL[Order],NULL,
+		                             "class=\"BT_LINK\"");
 		     if (Order == Questions->SelectedOrder)
 			HTM_U_Begin ();
 	      }
diff --git a/swad_record.c b/swad_record.c
index 2bc9a1d9..73124e3f 100644
--- a/swad_record.c
+++ b/swad_record.c
@@ -1406,9 +1406,8 @@ static void Rec_ShowLinkToPrintPreviewOfRecords (void)
    extern const char *Txt_record_cards_per_page;
    unsigned i;
 
-   HTM_BUTTON_OnSubmit_Begin (Txt_Print,
-                              The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme],
-                              NULL);
+   HTM_BUTTON_OnSubmit_Begin (Txt_Print,NULL,
+                              "class=\"%s\"",The_ClassFormLinkOutBoxBold[Gbl.Prefs.Theme]);
       Ico_PutIconTextLink ("print.svg",Ico_BLACK,Txt_Print);
    HTM_BUTTON_End ();
 
@@ -2578,7 +2577,8 @@ static void Rec_ShowInstitutionInHead (struct Ins_Instit *Ins,bool PutFormLinks)
 	   {
 	    Frm_BeginFormGoTo (ActSeeInsInf);
 	       Ins_PutParamInsCod (Ins->InsCod);
-	       HTM_BUTTON_OnSubmit_Begin (Ins->FullName,"BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Ins->FullName,NULL,
+	                                  "class=\"BT_LINK\"");
 	   }
 	 Lgo_DrawLogo (HieLvl_INS,Ins->InsCod,Ins->ShrtName,
 		       Rec_INSTITUTION_LOGO_SIZE,NULL,true);
@@ -2599,7 +2599,8 @@ static void Rec_ShowInstitutionInHead (struct Ins_Instit *Ins,bool PutFormLinks)
 	   {
 	    Frm_BeginFormGoTo (ActSeeInsInf);
 	       Ins_PutParamInsCod (Ins->InsCod);
-	       HTM_BUTTON_OnSubmit_Begin (Ins->FullName,"BT_LINK",NULL);
+	       HTM_BUTTON_OnSubmit_Begin (Ins->FullName,NULL,
+	                                  "class=\"BT_LINK\"");
 	   }
 	 HTM_Txt (Ins->FullName);
 	 if (PutFormLinks)
@@ -2679,7 +2680,8 @@ static void Rec_ShowNickname (struct UsrData *UsrDat,bool PutFormLinks)
 		  Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
 		  HTM_BUTTON_OnSubmit_Begin (ItsMe ? Txt_My_public_profile :
 						     Txt_Another_user_s_profile,
-					     "BT_LINK",NULL);
+					     NULL,
+					     "class=\"BT_LINK\"");
 	      }
 	    HTM_TxtF ("@%s",UsrDat->Nickname);
 	    if (PutFormLinks)
diff --git a/swad_room.c b/swad_room.c
index 2d9cb923..cb33e85b 100644
--- a/swad_room.c
+++ b/swad_room.c
@@ -185,8 +185,8 @@ void Roo_SeeRooms (void)
             HTM_TH_Begin (HTM_HEAD_LEFT);
 	       Frm_BeginForm (ActSeeRoo);
 		  Par_PutHiddenParamUnsigned (NULL,"Order",(unsigned) Order);
-		  HTM_BUTTON_OnSubmit_Begin (Txt_ROOMS_HELP_ORDER[Order],
-		                             "BT_LINK",NULL);
+		  HTM_BUTTON_OnSubmit_Begin (Txt_ROOMS_HELP_ORDER[Order],NULL,
+		                             "class=\"BT_LINK\"");
 		     if (Order == Rooms.SelectedOrder)
 			HTM_U_Begin ();
 		     HTM_Txt (Txt_ROOMS_ORDER[Order]);
diff --git a/swad_statistic.c b/swad_statistic.c
index f354e80d..58c963ae 100644
--- a/swad_statistic.c
+++ b/swad_statistic.c
@@ -1152,7 +1152,8 @@ static void Sta_ShowDetailedAccessesList (const struct Sta_Stats *Stats,
 		    {
 		     if (asprintf (&Title,Txt_Show_previous_X_clicks,Stats->RowsPerPage) < 0)
 			Err_NotEnoughMemoryExit ();
-		     HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+		                                "class=\"BT_LINK\"");
 		     free (Title);
 			HTM_TxtF ("&lt;%s",Txt_PAGES_Previous);
 		     HTM_BUTTON_End ();
@@ -1186,7 +1187,8 @@ static void Sta_ShowDetailedAccessesList (const struct Sta_Stats *Stats,
 		    {
 		     if (asprintf (&Title,Txt_Show_next_X_clicks,Stats->RowsPerPage) < 0)
 			Err_NotEnoughMemoryExit ();
-		     HTM_BUTTON_OnSubmit_Begin (Title,"BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Title,NULL,
+		                                "class=\"BT_LINK\"");
 		     free (Title);
 			HTM_TxtF ("%s&gt;",Txt_PAGES_Next);
 		     HTM_BUTTON_End ();
@@ -3296,7 +3298,7 @@ static void Sta_ShowNumHitsPerCourse (Sta_CountType_t CountType,
 	       Frm_BeginFormGoTo (ActSeeCrsInf);
 		  Crs_PutParamCrsCod (Crs.CrsCod);
 		  HTM_BUTTON_OnSubmit_Begin (Str_BuildGoToTitle (Crs.FullName),
-		                             "BT_LINK",NULL);
+		                             NULL,"class=\"BT_LINK\"");
 		  Str_FreeGoToTitle ();
 		     HTM_Txt (Crs.ShrtName);
 		  HTM_BUTTON_End ();
diff --git a/swad_survey.c b/swad_survey.c
index 82d09dfd..d48a783f 100644
--- a/swad_survey.c
+++ b/swad_survey.c
@@ -258,7 +258,7 @@ static void Svy_ListAllSurveys (struct Svy_Surveys *Surveys)
 			Pag_PutHiddenParamPagNum (Pag_SURVEYS,Surveys->CurrentPage);
 			Dat_PutHiddenParamOrder (Order);
 			HTM_BUTTON_OnSubmit_Begin (Txt_START_END_TIME_HELP[Order],
-						   "BT_LINK",NULL);
+			                           NULL,"class=\"BT_LINK\"");
 			   if (Order == Surveys->SelectedOrder)
 			      HTM_U_Begin ();
 			   HTM_Txt (Txt_START_END_TIME[Order]);
@@ -538,7 +538,8 @@ static void Svy_ShowOneSurvey (struct Svy_Surveys *Surveys,
 	    WhichGroups = Grp_GetParamWhichGroups ();
 	    Grp_PutParamWhichGroups (&WhichGroups);
 	    Pag_PutHiddenParamPagNum (Pag_SURVEYS,Surveys->CurrentPage);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_View_survey,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_View_survey,NULL,
+	                               "class=\"BT_LINK\"");
 	       HTM_Txt (Svy.Title);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
diff --git a/swad_system_config.c b/swad_system_config.c
index 384c6779..18d9ba3d 100644
--- a/swad_system_config.c
+++ b/swad_system_config.c
@@ -311,7 +311,7 @@ static void SysCfg_NumCtys (void)
       /* Data */
       HTM_TD_Begin ("class=\"LB DAT_%s\"",The_Colors[Gbl.Prefs.Theme]);
 	 Frm_BeginFormGoTo (ActSeeCty);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Countries,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Countries,NULL,"class=\"BT_LINK\"");
 	       HTM_Unsigned (Cty_GetCachedNumCtysInSys ());
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
diff --git a/swad_tab.c b/swad_tab.c
index b002cf11..8daa5205 100644
--- a/swad_tab.c
+++ b/swad_tab.c
@@ -119,8 +119,8 @@ void Tab_DrawTabs (void)
 
 		  Frm_BeginForm (ActMnu);
 		     Par_PutHiddenParamUnsigned (NULL,"NxtTab",(unsigned) NumTab);
-		     HTM_BUTTON_OnSubmit_Begin (Txt_TABS_TXT[NumTab],
-		                                "BT_LINK",NULL);
+		     HTM_BUTTON_OnSubmit_Begin (Txt_TABS_TXT[NumTab],NULL,
+		                                "class=\"BT_LINK\"");
 			HTM_IMG (Gbl.Prefs.URLIconSet,Tab_GetIcon (NumTab),Txt_TABS_TXT[NumTab],
 				 "class=\"TAB_ICO%s\"",ClassIcoTab[Gbl.Prefs.IconSet][Gbl.Prefs.Theme]);
 			HTM_DIV_Begin ("class=\"TAB_TXT TAB_%s_TXT_%s\"",
diff --git a/swad_theme.c b/swad_theme.c
index f7b35235..c50b6f57 100644
--- a/swad_theme.c
+++ b/swad_theme.c
@@ -133,17 +133,6 @@ const char *The_ClassFormInBoxNoWrap[The_NUM_THEMES] =
    [The_THEME_DARK  ] = "FORM_IN_DARK NOWRAP",
   };
 
-const char *The_ClassFormLinkOutBox[The_NUM_THEMES] =
-  {
-   [The_THEME_WHITE ] = "BT_LINK FORM_OUT_WHITE",
-   [The_THEME_GREY  ] = "BT_LINK FORM_OUT_GREY",
-   [The_THEME_PURPLE] = "BT_LINK FORM_OUT_PURPLE",
-   [The_THEME_BLUE  ] = "BT_LINK FORM_OUT_BLUE",
-   [The_THEME_YELLOW] = "BT_LINK FORM_OUT_YELLOW",
-   [The_THEME_PINK  ] = "BT_LINK FORM_OUT_PINK",
-   [The_THEME_DARK  ] = "BT_LINK FORM_OUT_DARK",
-  };
-
 const char *The_ClassFormOutBox[The_NUM_THEMES] =
   {
    [The_THEME_WHITE ] = "FORM_OUT_WHITE",
diff --git a/swad_timeline_comment.c b/swad_timeline_comment.c
index c575c0e1..0b60455f 100644
--- a/swad_timeline_comment.c
+++ b/swad_timeline_comment.c
@@ -623,7 +623,6 @@ static void TmlCom_WriteAuthorName (const struct UsrData *UsrDat)	// Author
    extern const char *The_Colors[The_NUM_THEMES];
    extern const char *Txt_My_public_profile;
    extern const char *Txt_Another_user_s_profile;
-   char *Class;
 
    /***** Show user's name inside form to go to user's public profile *****/
    /* Begin form */
@@ -631,13 +630,11 @@ static void TmlCom_WriteAuthorName (const struct UsrData *UsrDat)	// Author
       Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
 
       /* Author's name */
-      if (asprintf (&Class,"Tml_COM_AUTHOR Tml_COM_AUTHOR_WIDTH BT_LINK DAT_%s BOLD",
-                    The_Colors[Gbl.Prefs.Theme]) < 0)
-	 Err_NotEnoughMemoryExit ();
       HTM_BUTTON_OnSubmit_Begin (Usr_ItsMe (UsrDat->UsrCod) ? Txt_My_public_profile :
 							      Txt_Another_user_s_profile,
-			         Class,NULL);
-      free (Class);
+				 NULL,
+			         "class=\"Tml_COM_AUTHOR Tml_COM_AUTHOR_WIDTH BT_LINK DAT_%s BOLD\"",
+                                 The_Colors[Gbl.Prefs.Theme]);
 	 HTM_Txt (UsrDat->FullName);
       HTM_BUTTON_End ();
 
diff --git a/swad_timeline_form.c b/swad_timeline_form.c
index 0ceeac95..f26ea700 100644
--- a/swad_timeline_form.c
+++ b/swad_timeline_form.c
@@ -295,7 +295,7 @@ void TmlFrm_FormToShowHiddenComms (long NotCod,
 				   char IdComms[Frm_MAX_BYTES_ID + 1],
 				   unsigned NumInitialComms)
   {
-   extern const char *The_ClassFormLinkInBox[The_NUM_THEMES];
+   extern const char *The_Colors[The_NUM_THEMES];
    extern const char *Txt_See_the_previous_X_COMMENTS;
    char *OnSubmit;
    const char *Anchor;
@@ -345,9 +345,9 @@ void TmlFrm_FormToShowHiddenComms (long NotCod,
 	 free (OnSubmit);
 
 	    /* Put icon and text with link to show the first hidden comments */
-	    HTM_BUTTON_OnSubmit_Begin (NULL,
-	                               The_ClassFormLinkInBox[Gbl.Prefs.Theme],
-	                               NULL);
+	    HTM_BUTTON_OnSubmit_Begin (NULL,NULL,
+	                               "class=\"BT_LINK FORM_IN_%s\"",
+	                               The_Colors[Gbl.Prefs.Theme]);
 	       if (asprintf (&Text,Txt_See_the_previous_X_COMMENTS,NumInitialComms) < 0)
 		  Err_NotEnoughMemoryExit ();
 	       Ico_PutIconTextLink ("angle-up.svg",Ico_BLACK,Text);
diff --git a/swad_timeline_note.c b/swad_timeline_note.c
index 741a9d68..14d561bf 100644
--- a/swad_timeline_note.c
+++ b/swad_timeline_note.c
@@ -357,7 +357,8 @@ void TmlNot_WriteAuthorName (const struct UsrData *UsrDat,
       /* Author's name */
       HTM_BUTTON_OnSubmit_Begin (Usr_ItsMe (UsrDat->UsrCod) ? Txt_My_public_profile :
 							      Txt_Another_user_s_profile,
-			         Class,NULL);
+				 NULL,
+			         "class=\"%s\"",Class);
 	 HTM_Txt (UsrDat->FullName);
       HTM_BUTTON_End ();
 
@@ -598,7 +599,6 @@ static void TmlNot_PutFormGoToAction (const struct TmlNot_Note *Not,
       /* Analytics tab */
       /* Profile tab */
      };
-   char *Class;
 
    if (Not->Unavailable ||	// File/notice... pointed by this note is unavailable
        Gbl.Form.Inside)		// Inside another form
@@ -689,11 +689,9 @@ static void TmlNot_PutFormGoToAction (const struct TmlNot_Note *Not,
 
 	    /***** Icon and link to go to action *****/
 	    /* Begin button */
-	    if (asprintf (&Class,"BT_LINK %s ICO_HIGHLIGHT",
-	                  The_ClassFormInBoxBold[Gbl.Prefs.Theme]) < 0)
-	       Err_NotEnoughMemoryExit ();
-	    HTM_BUTTON_OnSubmit_Begin (Txt_TIMELINE_NOTE[Not->Type],Class,NULL);
-	    free (Class);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_TIMELINE_NOTE[Not->Type],NULL,
+	                               "class=\"BT_LINK %s ICO_HIGHLIGHT\"",
+	                               The_ClassFormInBoxBold[Gbl.Prefs.Theme]);
 
 	       /* Icon and text */
 	       Ico_PutIcon (Tml_Icons[Not->Type],Ico_BLACK,
diff --git a/swad_timeline_post.c b/swad_timeline_post.c
index d480d803..0b1768ca 100644
--- a/swad_timeline_post.c
+++ b/swad_timeline_post.c
@@ -243,7 +243,8 @@ void TmlPst_PutTextarea (const char *Placeholder,const char *ClassTextArea)
       free (ClassInput);
 
       /***** Submit button *****/
-      HTM_BUTTON_OnSubmit_Begin (NULL,"BT_SUBMIT_INLINE BT_CREATE",NULL);
+      HTM_BUTTON_OnSubmit_Begin (NULL,NULL,
+                                 "class=\"BT_SUBMIT_INLINE BT_CREATE\"");
 	 HTM_Txt (Txt_Post);
       HTM_BUTTON_End ();
 
diff --git a/swad_user.c b/swad_user.c
index 397d70db..76ed1189 100644
--- a/swad_user.c
+++ b/swad_user.c
@@ -1366,7 +1366,7 @@ void Usr_WriteLoggedUsrHead (void)
       if (NumAvailableRoles == 1)
 	{
 	 Frm_BeginForm (ActFrmRolSes);
-	    HTM_BUTTON_OnSubmit_Begin (Txt_Role,"BT_LINK",NULL);
+	    HTM_BUTTON_OnSubmit_Begin (Txt_Role,NULL,"class=\"BT_LINK\"");
 	       HTM_Txt (Txt_ROLES_SINGUL_Abc[Gbl.Usrs.Me.Role.Logged][Gbl.Usrs.Me.UsrDat.Sex]);
 	    HTM_BUTTON_End ();
 	 Frm_EndForm ();
@@ -3675,9 +3675,9 @@ static void Set_FormToSelectUsrListType (void (*FuncParams) (void *Args),void *A
 
       /***** Link and image *****/
       HTM_BUTTON_OnSubmit_Begin (Txt_USR_LIST_TYPES[ListType],
-			         The_ClassFormLinkInBoxNoWrap[Gbl.Prefs.Theme],
 			         Gbl.Action.Act == ActReqMsgUsr ? "CopyMessageToHiddenFields();" :
-								  NULL);
+								  NULL,
+			         "class=\"%s\"",The_ClassFormLinkInBoxNoWrap[Gbl.Prefs.Theme]);
 	 Ico_PutIcon (Usr_IconsClassPhotoOrList[ListType],Ico_BLACK,
 	              Txt_USR_LIST_TYPES[ListType],"ICO20x20");
 	 HTM_TxtF ("&nbsp;%s",Txt_USR_LIST_TYPES[ListType]);
@@ -6462,7 +6462,8 @@ void Usr_ShowTableCellWithUsrData (struct UsrData *UsrDat,unsigned NumRows)
       /* Begin form to go to user's record card */
       Frm_BeginForm (NextAction[UsrDat->Roles.InCurrentCrs]);
 	 Usr_PutParamUsrCodEncrypted (UsrDat->EnUsrCod);
-	 HTM_BUTTON_OnSubmit_Begin (UsrDat->FullName,"BT_LINK AUTHOR_TXT",NULL);
+	 HTM_BUTTON_OnSubmit_Begin (UsrDat->FullName,NULL,
+	                            "class=\"BT_LINK AUTHOR_TXT\"");
      }
 
    /* User's ID */