diff --git a/swad_attendance.c b/swad_attendance.c
index bfae516c..26e5f3b1 100644
--- a/swad_attendance.c
+++ b/swad_attendance.c
@@ -3578,7 +3578,7 @@ static void Att_ListAttEventsForAStd (unsigned NumUsr,struct UsrData *UsrDat)
 
 	 /***** Write a row for this event *****/
 	 Tbl_StartRow ();
-	 Tbl_PutEmptyCells (1);
+	 Tbl_PutEmptyColouredCells (1);
 	 fprintf (Gbl.F.Out,"<td class=\"%s RIGHT_TOP COLOR%u\">"
 			    "%u:"
 			    "</td>"
@@ -3610,7 +3610,7 @@ static void Att_ListAttEventsForAStd (unsigned NumUsr,struct UsrData *UsrDat)
 	 if (ShowCommentStd || ShowCommentTch)
 	   {
 	    Tbl_StartRow ();
-	    Tbl_PutEmptyCells (2);
+	    Tbl_PutEmptyColouredCells (2);
 	    fprintf (Gbl.F.Out,"<td class=\"BT%u\"></td>"
 			       "<td class=\"DAT LEFT_MIDDLE COLOR%u\">"
 	                       "<dl>",
diff --git a/swad_banner.c b/swad_banner.c
index 5d639f1c..a173b740 100644
--- a/swad_banner.c
+++ b/swad_banner.c
@@ -866,8 +866,8 @@ static void Ban_PutFormToCreateBanner (void)
    /***** Banner code *****/
    Tbl_StartRow ();
    fprintf (Gbl.F.Out,"<td class=\"BM\"></td>"
-                      "<td class=\"BM\"></td>"
-                      "<td></td>");
+                      "<td class=\"BM\"></td>");
+   Tbl_PutEmptyCells (1);
 
    /***** Banner short name *****/
    fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\">"
diff --git a/swad_changelog.h b/swad_changelog.h
index 6cc8af8d..59a6c560 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -487,12 +487,13 @@ enscript -2 --landscape --color --file-align=2 --highlight --line-numbers -o - *
 En OpenSWAD:
 ps2pdf source.ps destination.pdf
 */
-#define Log_PLATFORM_VERSION	"SWAD 19.31.5 (2019-10-05)"
+#define Log_PLATFORM_VERSION	"SWAD 19.31.6 (2019-10-05)"
 #define CSS_FILE		"swad19.29.css"
 #define JS_FILE			"swad19.30.js"
 /*
 // TODO: Perico: poner un candado de bloqueo de creación/edición de proyectos (por ejemplo en asignaturas obsoletas)
 
+	Version 19.31.6:  Oct 05, 2019	Code refactoring in HTML tables. (247066 lines)
 	Version 19.31.5:  Oct 05, 2019	Code refactoring in HTML tables. (247044 lines)
 	Version 19.31.4:  Oct 04, 2019	Code refactoring in HTML tables. (247043 lines)
 	Version 19.31.3:  Oct 04, 2019	Code refactoring in HTML tables. (247039 lines)
diff --git a/swad_country.c b/swad_country.c
index b93056bf..1a64273c 100644
--- a/swad_country.c
+++ b/swad_country.c
@@ -1610,8 +1610,9 @@ static void Cty_ListCountriesForEdition (void)
      {
       Cty = &Gbl.Hierarchy.Sys.Ctys.Lst[NumCty];
 
-      /* Put icon to remove country */
       Tbl_StartRow ();
+
+      /* Put icon to remove country */
       fprintf (Gbl.F.Out,"<td rowspan=\"%u\" class=\"BT\">",
 	       1 + Lan_NUM_LANGUAGES);
       if (Cty->Inss.Num ||
@@ -1639,9 +1640,7 @@ static void Cty_ListCountriesForEdition (void)
 	                 "</td>",
                1 + Lan_NUM_LANGUAGES,Cty->Alpha2);
 
-      fprintf (Gbl.F.Out,"<td></td>"
-	                 "<td></td>"
-	                 "<td></td>");
+      Tbl_PutEmptyCells (3);
 
       /* Number of users */
       fprintf (Gbl.F.Out,"<td rowspan=\"%u\" class=\"DAT RIGHT_TOP\">"
@@ -1654,6 +1653,7 @@ static void Cty_ListCountriesForEdition (void)
 	                 "%u"
 	                 "</td>",
                1 + Lan_NUM_LANGUAGES,Cty->Inss.Num);
+
       Tbl_EndRow ();
 
       /* Country name in several languages */
@@ -1661,8 +1661,9 @@ static void Cty_ListCountriesForEdition (void)
 	   Lan <= Lan_NUM_LANGUAGES;
 	   Lan++)
         {
-	 /* Language */
          Tbl_StartRow ();
+
+	 /* Language */
          fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_MIDDLE\">"
                             "%s:"
                             "</td>",
@@ -1694,6 +1695,7 @@ static void Cty_ListCountriesForEdition (void)
                   Cty->WWW[Lan],Gbl.Form.Id);
          Frm_EndForm ();
          fprintf (Gbl.F.Out,"</td>");
+
          Tbl_EndRow ();
         }
      }
@@ -2048,8 +2050,9 @@ static void Cty_PutFormToCreateCountry (void)
    /***** Write heading *****/
    Cty_PutHeadCountriesForEdition ();
 
-   /***** Column to remove country, disabled here *****/
    Tbl_StartRow ();
+
+   /***** Column to remove country, disabled here *****/
    fprintf (Gbl.F.Out,"<td rowspan=\"%u\" class=\"BT\"></td>",
             1 + Lan_NUM_LANGUAGES);
 
@@ -2071,21 +2074,20 @@ static void Cty_PutFormToCreateCountry (void)
                       "</td>",
             1 + Lan_NUM_LANGUAGES,Cty_EditingCty->Alpha2);
 
-   fprintf (Gbl.F.Out,"<td></td>"
-		      "<td></td>"
-		      "<td></td>");
+   Tbl_PutEmptyCells (3);
 
-   /* Number of users */
+   /***** Number of users *****/
    fprintf (Gbl.F.Out,"<td rowspan=\"%u\" class=\"DAT RIGHT_TOP\">"
 	              "0"
 	              "</td>",
 	    1 + Lan_NUM_LANGUAGES);
 
-   /* Number of institutions */
+   /***** Number of institutions *****/
    fprintf (Gbl.F.Out,"<td rowspan=\"%u\" class=\"DAT RIGHT_TOP\">"
 	              "0"
 	              "</td>",
 	    1 + Lan_NUM_LANGUAGES);
+
    Tbl_EndRow ();
 
    /***** Country name in several languages *****/
@@ -2093,8 +2095,9 @@ static void Cty_PutFormToCreateCountry (void)
 	Lan <= Lan_NUM_LANGUAGES;
 	Lan++)
      {
-      /* Language */
       Tbl_StartRow ();
+
+      /* Language */
       fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP\">"
 	                 "%s"
 	                 "</td>",
@@ -2119,6 +2122,7 @@ static void Cty_PutFormToCreateCountry (void)
 	       Lan_STR_LANG_ID[Lan],
 	       Cns_MAX_CHARS_WWW,
 	       Cty_EditingCty->WWW[Lan]);
+
       Tbl_EndRow ();
      }
 
diff --git a/swad_file_browser.c b/swad_file_browser.c
index 49a39266..2aaf0308 100644
--- a/swad_file_browser.c
+++ b/swad_file_browser.c
@@ -8534,7 +8534,7 @@ static void Brw_PutFormToCreateALink (const char *FileNameToShow)
                       "<input type=\"text\""
                       " id=\"NewLinkName\" name=\"NewLinkName\""
                       " size=\"30\" maxlength=\"%u\" value=\"\" />"
-                      "</td>"
+                      "</td>",
             The_ClassFormInBox[Gbl.Prefs.Theme],Txt_Save_as,Txt_optional,
             Brw_MAX_CHARS_FOLDER);
    Tbl_EndRow ();
diff --git a/swad_group.c b/swad_group.c
index 990659bd..888b773e 100644
--- a/swad_group.c
+++ b/swad_group.c
@@ -2275,6 +2275,7 @@ static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp,
    /* Write checkbox to select the group */
    ICanSelUnselGroup = (Gbl.Usrs.Me.Role.Logged >= Rol_STD);
    Tbl_StartRow ();
+
    fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">"
                       "<input type=\"checkbox\" id=\"Grp%ld\" name=\"GrpCods\""
                       " value=\"%ld\"",
@@ -2322,9 +2323,9 @@ static void Grp_ListGrpsForMultipleSelection (struct GroupType *GrpTyp,
 			 "</td>",
 	       Grp_CountNumUsrsInNoGrpsOfType (Role,GrpTyp->GrpTypCod));
 
-   /* Last void columns for max. students and vacants */
-   fprintf (Gbl.F.Out,"<td></td>"
-	              "<td></td>");
+   /* Last empty columns for max. students and vacants */
+   Tbl_PutEmptyCells (2);
+
    Tbl_EndRow ();
   }
 
diff --git a/swad_holiday.c b/swad_holiday.c
index f5dbf180..5aecd561 100644
--- a/swad_holiday.c
+++ b/swad_holiday.c
@@ -992,8 +992,9 @@ static void Hld_PutFormToCreateHoliday (void)
             Txt_Holiday);
    Tbl_EndRow ();
 
-   /***** Holiday place *****/
    Tbl_StartRow ();
+
+   /***** Holiday place *****/
    fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\">"
                       "<select name=\"PlcCod\" style=\"width:62px;\">"
                       "<option value=\"-1\"");
@@ -1048,9 +1049,11 @@ static void Hld_PutFormToCreateHoliday (void)
                       "<input type=\"text\" name=\"Name\""
                       " size=\"20\" maxlength=\"%u\" value=\"%s\""
                       " required=\"required\" />"
-                      "</td>"
-                      "<td></td>",
+                      "</td>",
             Hld_MAX_CHARS_HOLIDAY_NAME,Hld_EditingHld->Name);
+
+   Tbl_PutEmptyCells (1);
+
    Tbl_EndRow ();
 
    /***** End table, send button and end box *****/
diff --git a/swad_link.c b/swad_link.c
index df6617c7..be64b03f 100644
--- a/swad_link.c
+++ b/swad_link.c
@@ -745,10 +745,11 @@ static void Lnk_PutFormToCreateLink (void)
    /***** Write heading *****/
    Lnk_PutHeadLinks ();
 
-   /***** Link code *****/
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td class=\"BM\"></td>"
-                      "<td></td>");
+
+   /***** Link code *****/
+   fprintf (Gbl.F.Out,"<td class=\"BM\"></td>");
+   Tbl_PutEmptyCells (1);
 
    /***** Link short name *****/
    fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\">"
@@ -776,6 +777,7 @@ static void Lnk_PutFormToCreateLink (void)
                       " required=\"required\" />"
                       "</td>",
             Cns_MAX_CHARS_WWW,Lnk_EditingLnk->WWW);
+
    Tbl_EndRow ();
 
    /***** End table, send button and end box *****/
diff --git a/swad_mail.c b/swad_mail.c
index f3157a1a..9d72eb33 100644
--- a/swad_mail.c
+++ b/swad_mail.c
@@ -762,8 +762,9 @@ static void Mai_PutFormToCreateMailDomain (void)
             Txt_EMAIL_DOMAIN_ORDER[Mai_ORDER_BY_INFO  ]);
    Tbl_EndRow ();
 
-   /***** Mail domain *****/
    Tbl_StartRow ();
+
+   /***** Mail domain *****/
    fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\">"
                       "<input type=\"text\" name=\"Domain\""
                       " size=\"15\" maxlength=\"%u\" value=\"%s\""
@@ -776,11 +777,12 @@ static void Mai_PutFormToCreateMailDomain (void)
                       "<input type=\"text\" name=\"Info\""
                       " size=\"40\" maxlength=\"%u\" value=\"%s\""
                       " required=\"required\" />"
-                      "</td>"
-                      "<td></td>",
+                      "</td>",
             Mai_MAX_CHARS_MAIL_INFO,Mai_EditingMai->Info);
-   Tbl_EndRow ();
 
+   Tbl_PutEmptyCells (1);
+
+   Tbl_EndRow ();
 
    /***** End table, send button and end box *****/
    Box_EndBoxTableWithButton (Btn_CREATE_BUTTON,Txt_Create_email_domain);
diff --git a/swad_mark.c b/swad_mark.c
index b02fc4f0..996d00d1 100644
--- a/swad_mark.c
+++ b/swad_mark.c
@@ -114,7 +114,7 @@ void Mrk_GetAndWriteNumRowsHeaderAndFooter (void)
    struct MarksProperties Marks;
 
    if (Gbl.FileBrowser.FilFolLnk.Type == Brw_IS_FOLDER)
-      Tbl_PutEmptyCells (2);
+      Tbl_PutEmptyColouredCells (2);
    else	// File or link
      {
       /***** Get number of rows in header or footer *****/
diff --git a/swad_match.c b/swad_match.c
index 5e0059d7..348559be 100644
--- a/swad_match.c
+++ b/swad_match.c
@@ -3147,7 +3147,7 @@ static void Mch_DrawBarNumUsrs (unsigned NumAnswerersAns,unsigned NumAnswerersQs
 
    /***** Bar proportional to number of users *****/
    Tbl_StartTableWide ();
-   fprintf (Gbl.F.Out,"<tr class=\"MATCH_RES_TR\">");
+   Tbl_StartClass ("MATCH_RES_TR");
    for (i = 0;
 	i < 100;
 	i++)
diff --git a/swad_match_result.c b/swad_match_result.c
index ec750169..c9ae097e 100644
--- a/swad_match_result.c
+++ b/swad_match_result.c
@@ -561,7 +561,7 @@ static void McR_ShowMchResults (Usr_MeOrOther_t MeOrOther)
      }
    else
      {
-      Tbl_PutEmptyCells (8);
+      Tbl_PutEmptyColouredCells (8);
       Tbl_EndRow ();
      }
 
diff --git a/swad_survey.c b/swad_survey.c
index c3ecba21..86bded60 100644
--- a/swad_survey.c
+++ b/swad_survey.c
@@ -2720,10 +2720,12 @@ static void Svy_ShowFormEditOneQst (long SvyCod,struct SurveyQuestion *SvyQst,
    Tbl_EndRow ();
 
    /***** Answers *****/
-   /* Unique or multiple choice answers */
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td></td>"
-                      "<td class=\"LEFT_TOP\">");
+
+   Tbl_PutEmptyCells (1);
+
+   /* Unique or multiple choice answers */
+   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">");
    Tbl_StartTablePadding (2);
    for (NumAns = 0;
 	NumAns < Svy_MAX_ANSWERS_PER_QUESTION;
@@ -2749,6 +2751,7 @@ static void Svy_ShowFormEditOneQst (long SvyCod,struct SurveyQuestion *SvyQst,
      }
    Tbl_EndTable ();
    fprintf (Gbl.F.Out,"</td>");
+
    Tbl_EndRow ();
 
    /***** End table *****/
diff --git a/swad_table.c b/swad_table.c
index 411249f1..0a102013 100644
--- a/swad_table.c
+++ b/swad_table.c
@@ -161,6 +161,23 @@ void Tbl_EndTable (void)
 	    "</table>");
   }
 
+void Tbl_StartClass (const char *Class)
+  {
+   if (Class)
+     {
+      if (Class[0])
+	{
+	 fprintf (Gbl.F.Out,
+		  "<tr class=\"%s\">",
+		  Class);
+	}
+      else
+	 Tbl_StartRow ();
+     }
+   else
+      Tbl_StartRow ();
+  }
+
 void Tbl_StartRow (void)
   {
    fprintf (Gbl.F.Out,
@@ -174,6 +191,17 @@ void Tbl_EndRow (void)
   }
 
 void Tbl_PutEmptyCells (unsigned NumColumns)
+  {
+   unsigned NumCol;
+
+   for (NumCol = 0;
+	NumCol < NumColumns;
+	NumCol++)
+      fprintf (Gbl.F.Out,
+	       "<td></td>");
+  }
+
+void Tbl_PutEmptyColouredCells (unsigned NumColumns)
   {
    unsigned NumCol;
 
diff --git a/swad_table.h b/swad_table.h
index 3839183e..e06f7245 100644
--- a/swad_table.h
+++ b/swad_table.h
@@ -55,9 +55,11 @@ void Tbl_StartTableWideMargin (void);
 
 void Tbl_EndTable (void);
 
+void Tbl_StartClass (const char *Class);
 void Tbl_StartRow (void);
 void Tbl_EndRow (void);
 
 void Tbl_PutEmptyCells (unsigned NumColumns);
+void Tbl_PutEmptyColouredCells (unsigned NumColumns);
 
 #endif
diff --git a/swad_test.c b/swad_test.c
index 32276dfe..41a424b8 100644
--- a/swad_test.c
+++ b/swad_test.c
@@ -1709,7 +1709,7 @@ static void Tst_ShowFormSelTags (unsigned long NumRows,MYSQL_RES *mysql_res,
    Tbl_StartTablePadding (2);
    Tbl_StartRow ();
    if (!ShowOnlyEnabledTags)
-      fprintf (Gbl.F.Out,"<td></td>");
+      Tbl_PutEmptyCells (1);
    fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">"
                       "<label class=\"%s\">"
 	              "<input type=\"checkbox\" name=\"AllTags\" value=\"Y\"",
@@ -3844,8 +3844,7 @@ static void Tst_WriteChoiceAnsAssessTest (struct UsrData *UsrDat,
    Tbl_StartTablePadding (2);
    Tbl_StartRow ();
    Tst_WriteHeadUserCorrect (UsrDat);
-   fprintf (Gbl.F.Out,"<td></td>"
-	              "<td></td>");
+   Tbl_PutEmptyCells (2);
    Tbl_EndRow ();
 
    /***** Write answers (one row per answer) *****/
@@ -3881,7 +3880,7 @@ static void Tst_WriteChoiceAnsAssessTest (struct UsrData *UsrDat,
 			    Ans.Class,Txt_TST_Answer_given_by_the_user,Ans.Str);
         }
       else	// This answer has NOT been selected by the user
-	 fprintf (Gbl.F.Out,"<td></td>");
+         Tbl_PutEmptyCells (1);
 
       /* Draw icon that indicates whether the answer is correct */
       if (Gbl.Test.Config.Feedback == Tst_FEEDBACK_EACH_GOOD_BAD ||
@@ -3891,7 +3890,7 @@ static void Tst_WriteChoiceAnsAssessTest (struct UsrData *UsrDat,
 	    fprintf (Gbl.F.Out,"<td class=\"ANS_0 CENTER_TOP\" title=\"%s\">&bull;</td>",
 		     Txt_TST_Answer_given_by_the_teachers);
          else
-	    fprintf (Gbl.F.Out,"<td></td>");
+            Tbl_PutEmptyCells (1);
         }
       else
 	 fprintf (Gbl.F.Out,"<td class=\"ANS_0 CENTER_TOP\">?</td>");
@@ -5229,8 +5228,8 @@ static void Tst_PutFormEditOneQst (char Stem[Cns_MAX_BYTES_TEXT + 1],
 
    /* Floating point answer */
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td></td>"
-                      "<td class=\"LEFT_TOP\">");
+   Tbl_PutEmptyCells (1);
+   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">");
    Tst_PutFloatInputField (Txt_Real_number_between_A_and_B_1,"AnsFloatMin",
                            Gbl.Test.Answer.FloatingPoint[0]);
    Tst_PutFloatInputField (Txt_Real_number_between_A_and_B_2,"AnsFloatMax",
@@ -5240,8 +5239,8 @@ static void Tst_PutFormEditOneQst (char Stem[Cns_MAX_BYTES_TEXT + 1],
 
    /* T/F answer */
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td></td>"
-                      "<td class=\"LEFT_TOP\">");
+   Tbl_PutEmptyCells (1);
+   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">");
    Tst_PutTFInputField (Txt_TF_QST[0],'T');
    Tst_PutTFInputField (Txt_TF_QST[1],'F');
    fprintf (Gbl.F.Out,"</td>");
@@ -5249,8 +5248,8 @@ static void Tst_PutFormEditOneQst (char Stem[Cns_MAX_BYTES_TEXT + 1],
 
    /* Questions can be shuffled? */
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td></td>"
-                      "<td class=\"LEFT_TOP\">"
+   Tbl_PutEmptyCells (1);
+   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">"
                       "<label class=\"%s\">"
                       "<input type=\"checkbox\" name=\"Shuffle\" value=\"Y\"",
             The_ClassFormInBox[Gbl.Prefs.Theme]);
@@ -5268,8 +5267,8 @@ static void Tst_PutFormEditOneQst (char Stem[Cns_MAX_BYTES_TEXT + 1],
 
    /* Simple or multiple choice answers */
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td></td>"
-	              "<td class=\"LEFT_TOP\">");
+   Tbl_PutEmptyCells (1);
+   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">");
    Tbl_StartTablePadding (2);	// Table with choice answers
 
    OptionsDisabled = Gbl.Test.AnswerType != Tst_ANS_UNIQUE_CHOICE &&
@@ -7890,7 +7889,7 @@ static void Tst_ShowTstResults (struct UsrData *UsrDat)
      }
    else
      {
-      Tbl_PutEmptyCells (7);
+      Tbl_PutEmptyColouredCells (7);
       Tbl_EndRow ();
      }