diff --git a/swad_changelog.h b/swad_changelog.h
index 6cfdd4366..a206d9585 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -487,7 +487,7 @@ enscript -2 --landscape --color --file-align=2 --highlight --line-numbers -o - *
 En OpenSWAD:
 ps2pdf source.ps destination.pdf
 */
-#define Log_PLATFORM_VERSION	"SWAD 19.31.29 (2019-10-08)"
+#define Log_PLATFORM_VERSION	"SWAD 19.31.30 (2019-10-08)"
 #define CSS_FILE		"swad19.29.css"
 #define JS_FILE			"swad19.30.js"
 /*
@@ -495,6 +495,7 @@ ps2pdf source.ps destination.pdf
 // TODO: Un TFG preasignado sin estudiante tiene que salir un triángulo amarillo
 // TODO: Hacer un nuevo rol en los TFG: tutor externo (profesor de áreas no vinculadas con el centro, profesionales de empresas, etc.)
 
+	Version 19.31.30: Oct 08, 2019	Code refactoring in HTML tables. (246731 lines)
 	Version 19.31.29: Oct 08, 2019	Code refactoring in HTML tables. (246740 lines)
 	Version 19.31.28: Oct 08, 2019	Code refactoring in HTML tables. (246783 lines)
 	Version 19.31.27: Oct 08, 2019	Code refactoring in HTML tables. (246823 lines)
diff --git a/swad_match.c b/swad_match.c
index f1a9f7b3e..708225d81 100644
--- a/swad_match.c
+++ b/swad_match.c
@@ -511,7 +511,7 @@ static bool Mch_CheckIfICanEditThisMatch (const struct Match *Match)
 
 static void Mch_ListOneOrMoreMatchesIcons (const struct Match *Match)
   {
-   fprintf (Gbl.F.Out,"<td class=\"BT%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"BT%u\"",Gbl.RowEvenOdd);
 
    /***** Put icon to remove the match *****/
    if (Mch_CheckIfICanEditThisMatch (Match))
@@ -536,7 +536,7 @@ static void Mch_ListOneOrMoreMatchesIcons (const struct Match *Match)
 static void Mch_ListOneOrMoreMatchesAuthor (const struct Match *Match)
   {
    /***** Match author (teacher) *****/
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"LEFT_TOP COLOR%u\"",Gbl.RowEvenOdd);
    Usr_WriteAuthor1Line (Match->UsrCod,false);
    Tbl_EndCell ();
   }
@@ -554,12 +554,11 @@ static void Mch_ListOneOrMoreMatchesTimes (const struct Match *Match,unsigned Un
 	StartEndTime <= (Dat_StartEndTime_t) (Dat_NUM_START_END_TIME - 1);
 	StartEndTime++)
      {
-      fprintf (Gbl.F.Out,"<td id=\"mch_time_%u_%u\""
-			 " class=\"%s LEFT_TOP COLOR%u\">",
-	       (unsigned) StartEndTime,UniqueId,
-	       Match->Status.QstInd >= Mch_AFTER_LAST_QUESTION ? "DATE_RED" :
-								 "DATE_GREEN",
-	       Gbl.RowEvenOdd);
+      Tbl_StartCellAttr ("id=\"mch_time_%u_%u\" class=\"%s LEFT_TOP COLOR%u\"",
+			 (unsigned) StartEndTime,UniqueId,
+			 Match->Status.QstInd >= Mch_AFTER_LAST_QUESTION ? "DATE_RED" :
+									   "DATE_GREEN",
+			 Gbl.RowEvenOdd);
       fprintf (Gbl.F.Out,"<script type=\"text/javascript\">"
 			 "writeLocalDateHMSFromUTC('mch_time_%u_%u',"
 			 "%ld,%u,'<br />','%s',true,true,0x7);"
@@ -577,7 +576,7 @@ static void Mch_ListOneOrMoreMatchesTimes (const struct Match *Match,unsigned Un
 
 static void Mch_ListOneOrMoreMatchesTitleGrps (const struct Match *Match)
   {
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"LEFT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 
    /***** Title *****/
    fprintf (Gbl.F.Out,"<span class=\"ASG_TITLE\">%s</span>",Match->Title);
@@ -660,7 +659,7 @@ static void Mch_GetAndWriteNamesOfGrpsAssociatedToMatch (const struct Match *Mat
 static void Mch_ListOneOrMoreMatchesNumPlayers (const struct Match *Match)
   {
    /***** Number of players who have answered any question in the match ******/
-   fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
    fprintf (Gbl.F.Out,"%u",Mch_GetNumUsrsWhoHaveAnswerMch (Match->MchCod));
    Tbl_EndCell ();
   }
@@ -675,7 +674,7 @@ static void Mch_ListOneOrMoreMatchesStatus (const struct Match *Match,unsigned N
    extern const char *Txt_Play;
    extern const char *Txt_Resume;
 
-   fprintf (Gbl.F.Out,"<td class=\"DAT CENTER_TOP COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT CENTER_TOP COLOR%u\"",Gbl.RowEvenOdd);
 
    if (Match->Status.QstInd < Mch_AFTER_LAST_QUESTION)	// Unfinished match
       /* Current question index / total of questions */
@@ -728,7 +727,7 @@ static void Mch_ListOneOrMoreMatchesResult (const struct Match *Match,
    extern const char *Txt_Hidden_result;
    extern const char *Txt_Visible_result;
 
-   fprintf (Gbl.F.Out,"<td class=\"DAT CENTER_TOP COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT CENTER_TOP COLOR%u\"",Gbl.RowEvenOdd);
 
    switch (Gbl.Usrs.Me.Role.Logged)
      {
@@ -1194,12 +1193,12 @@ static void Mch_PutFormNewMatch (struct Game *Game)
    /***** Match title *****/
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"Title\" class=\"%s\">%s:</label>",
             The_ClassFormInBox[Gbl.Prefs.Theme],Txt_Title);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<input type=\"text\" id=\"Title\" name=\"Title\""
                       " size=\"45\" maxlength=\"%u\" value=\"%s\""
                       " required=\"required\" />",
@@ -1251,18 +1250,17 @@ static void Mch_ShowLstGrpsToCreateMatch (void)
       /***** Start box and table *****/
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"%s RIGHT_TOP\">",
-               The_ClassFormInBox[Gbl.Prefs.Theme]);
+      Tbl_StartCellAttr ("class=\"%s RIGHT_TOP\"",The_ClassFormInBox[Gbl.Prefs.Theme]);
       fprintf (Gbl.F.Out,"%s:",Txt_Groups);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">");
+      Tbl_StartCellAttr ("class=\"LEFT_TOP\"");
       Box_StartBoxTable ("95%",NULL,NULL,
                          NULL,Box_NOT_CLOSABLE,0);
 
       /***** First row: checkbox to select the whole course *****/
       Tbl_StartRow ();
-      fprintf (Gbl.F.Out,"<td colspan=\"7\" class=\"DAT LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("colspan=\"7\" class=\"DAT LEFT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<label>"
                          "<input type=\"checkbox\""
                          " id=\"WholeCrs\" name=\"WholeCrs\" value=\"Y\""
@@ -2494,7 +2492,7 @@ static void Mch_ShowQuestionAndAnswersStd (struct Match *Match)
 
 	    /***** Write letter for this option *****/
 	    /* Start table cell */
-	    fprintf (Gbl.F.Out,"<td class=\"MATCH_STD_CELL\">");
+	    Tbl_StartCellAttr ("class=\"MATCH_STD_CELL\"");
 
 	    /* Form with button.
 	       Sumitting onmousedown instead of default onclick
@@ -3154,10 +3152,10 @@ static void Mch_DrawBarNumUsrs (unsigned NumAnswerersAns,unsigned NumAnswerersQs
 	i < 100;
 	i++)
      {
-      fprintf (Gbl.F.Out,"<td class=\"%s\">",
-	       (i < BarWidth) ? (Correct ? "MATCH_RES_CORRECT" :
-					   "MATCH_RES_WRONG") :
-				"MATCH_RES_VOID");
+      Tbl_StartCellAttr ("class=\"%s\"",
+			 (i < BarWidth) ? (Correct ? "MATCH_RES_CORRECT" :
+						     "MATCH_RES_WRONG") :
+					  "MATCH_RES_VOID");
       Tbl_EndCell ();
      }
    Tbl_EndRow ();
diff --git a/swad_match_result.c b/swad_match_result.c
index 8f81e039e..02de94c25 100644
--- a/swad_match_result.c
+++ b/swad_match_result.c
@@ -207,12 +207,11 @@ void McR_SelUsrsToViewUsrsMchResults (void)
          Tbl_StartTableCenterPadding (2);
          Tbl_StartRow ();
 
-         fprintf (Gbl.F.Out,"<td class=\"%s RIGHT_TOP\">",The_ClassFormInBox[Gbl.Prefs.Theme]);
+         Tbl_StartCellAttr ("class=\"%s RIGHT_TOP\"",The_ClassFormInBox[Gbl.Prefs.Theme]);
          fprintf (Gbl.F.Out,"%s:",Txt_Users);
          Tbl_EndCell ();
 
-	 fprintf (Gbl.F.Out,"<td colspan=\"2\" class=\"%s LEFT_TOP\">",
-                  The_ClassFormInBox[Gbl.Prefs.Theme]);
+	 Tbl_StartCellAttr ("colspan=\"2\" class=\"%s LEFT_TOP\"",The_ClassFormInBox[Gbl.Prefs.Theme]);
          Tbl_StartTablePadding (2);
          Usr_ListUsersToSelect (Rol_TCH);
          Usr_ListUsersToSelect (Rol_NET);
@@ -454,10 +453,9 @@ static void McR_ShowMchResults (Usr_MeOrOther_t MeOrOther)
            {
 	    TimeUTC[StartEndTime] = Dat_GetUNIXTimeFromStr (row[1 + StartEndTime]);
 	    UniqueId++;
-	    fprintf (Gbl.F.Out,"<td id =\"mch_time_%u_%u\""
-		               " class=\"DAT LEFT_TOP COLOR%u\">",
-		     (unsigned) StartEndTime,UniqueId,
-		     Gbl.RowEvenOdd);
+	    Tbl_StartCellAttr ("id =\"mch_time_%u_%u\" class=\"DAT LEFT_TOP COLOR%u\"",
+			       (unsigned) StartEndTime,UniqueId,
+			       Gbl.RowEvenOdd);
 	    fprintf (Gbl.F.Out,"<script type=\"text/javascript\">"
 			       "writeLocalDateHMSFromUTC('mch_time_%u_%u',"
 			       "%ld,%u,'<br />','%s',true,false,0x7);"
@@ -469,7 +467,7 @@ static void McR_ShowMchResults (Usr_MeOrOther_t MeOrOther)
            }
 
          /* Write match title */
-	 fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT LEFT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 fprintf (Gbl.F.Out,"%s",Match.Title);
 	 Tbl_EndCell ();
 
@@ -494,24 +492,24 @@ static void McR_ShowMchResults (Usr_MeOrOther_t MeOrOther)
 	   }
 
          /* Write number of questions */
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 fprintf (Gbl.F.Out,"%u",NumQstsInThisResult);
 	 Tbl_EndCell ();
 
          /* Write number of questions not blank */
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 fprintf (Gbl.F.Out,"%u",NumQstsNotBlankInThisResult);
 	 Tbl_EndCell ();
 
 	 /* Write score */
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 if (ShowResultThisMatch)
 	    fprintf (Gbl.F.Out,"%.2lf",
 		     ScoreInThisResult);
 	 Tbl_EndCell ();
 
          /* Write average score per question */
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 if (ShowResultThisMatch)
 	    fprintf (Gbl.F.Out,"%.2lf",
 		     NumQstsInThisResult ? ScoreInThisResult / (double) NumQstsInThisResult :
@@ -519,7 +517,7 @@ static void McR_ShowMchResults (Usr_MeOrOther_t MeOrOther)
 	 Tbl_EndCell ();
 
          /* Write score over Tst_SCORE_MAX */
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 if (ShowResultThisMatch)
 	    fprintf (Gbl.F.Out,"%.2lf",
 		     NumQstsInThisResult ? ScoreInThisResult * Tst_SCORE_MAX /
@@ -528,7 +526,7 @@ static void McR_ShowMchResults (Usr_MeOrOther_t MeOrOther)
 	 Tbl_EndCell ();
 
 	 /* Link to show this result */
-	 fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"RIGHT_TOP COLOR%u\"",Gbl.RowEvenOdd);
 	 if (ShowResultThisMatch)
 	   {
 	    Gam_SetParamCurrentGamCod (Match.GamCod);	// Used to pass parameter
@@ -589,30 +587,30 @@ static void McR_ShowMchResultsSummaryRow (bool ShowSummaryResults,
    Tbl_StartRow ();
 
    /***** Row title *****/
-   fprintf (Gbl.F.Out,"<td colspan=\"3\" class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("colspan=\"3\" class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
    fprintf (Gbl.F.Out,"%s: %u",Txt_Matches,NumResults);
    Tbl_EndCell ();
 
    /***** Write total number of questions *****/
-   fprintf (Gbl.F.Out,"<td class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
    if (NumResults)
       fprintf (Gbl.F.Out,"%u",NumTotalQsts);
    Tbl_EndCell ();
 
    /***** Write total number of questions not blank *****/
-   fprintf (Gbl.F.Out,"<td class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
    if (NumResults)
       fprintf (Gbl.F.Out,"%u",NumTotalQstsNotBlank);
    Tbl_EndCell ();
 
    /***** Write total score *****/
-   fprintf (Gbl.F.Out,"<td class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
    if (ShowSummaryResults)
       fprintf (Gbl.F.Out,"%.2lf",TotalScoreOfAllResults);
    Tbl_EndCell ();
 
    /***** Write average score per question *****/
-   fprintf (Gbl.F.Out,"<td class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
    if (ShowSummaryResults)
       fprintf (Gbl.F.Out,"%.2lf",
 	       NumTotalQsts ? TotalScoreOfAllResults / (double) NumTotalQsts :
@@ -620,7 +618,7 @@ static void McR_ShowMchResultsSummaryRow (bool ShowSummaryResults,
    Tbl_EndCell ();
 
    /***** Write score over Tst_SCORE_MAX *****/
-   fprintf (Gbl.F.Out,"<td class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT_N_LINE_TOP RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
    if (ShowSummaryResults)
       fprintf (Gbl.F.Out,"%.2lf",
 	       NumTotalQsts ? TotalScoreOfAllResults * Tst_SCORE_MAX /
@@ -629,7 +627,7 @@ static void McR_ShowMchResultsSummaryRow (bool ShowSummaryResults,
    Tbl_EndCell ();
 
    /***** Last cell *****/
-   fprintf (Gbl.F.Out,"<td class=\"DAT_N_LINE_TOP COLOR%u\">",Gbl.RowEvenOdd);
+   Tbl_StartCellAttr ("class=\"DAT_N_LINE_TOP COLOR%u\"",Gbl.RowEvenOdd);
    Tbl_EndCell ();
 
    /***** End row *****/
@@ -779,11 +777,11 @@ void McR_ShowOneMchResult (void)
       /* User */
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT_N RIGHT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT_N RIGHT_TOP\"");
       fprintf (Gbl.F.Out,"%s:",Txt_ROLES_SINGUL_Abc[UsrDat->Roles.InCurrentCrs.Role][UsrDat->Sex]);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT LEFT_TOP\"");
       ID_WriteUsrIDs (UsrDat,NULL);
       fprintf (Gbl.F.Out," %s",
 	       UsrDat->Surname1);
@@ -809,12 +807,12 @@ void McR_ShowOneMchResult (void)
 	{
 	 Tbl_StartRow ();
 
-	 fprintf (Gbl.F.Out,"<td class=\"DAT_N RIGHT_TOP\">");
+	 Tbl_StartCellAttr ("class=\"DAT_N RIGHT_TOP\"");
 	 fprintf (Gbl.F.Out,"%s:",Txt_START_END_TIME[StartEndTime]);
 	 Tbl_EndCell ();
 
-	 fprintf (Gbl.F.Out,"<td id=\"match_%u\" class=\"DAT LEFT_TOP\">",
-		  (unsigned) StartEndTime);
+	 Tbl_StartCellAttr ("id=\"match_%u\" class=\"DAT LEFT_TOP\"",
+		            (unsigned) StartEndTime);
 	 fprintf (Gbl.F.Out,"<script type=\"text/javascript\">"
 			    "writeLocalDateHMSFromUTC('match_%u',%ld,"
 			    "%u,',&nbsp;','%s',true,true,0x7);"
@@ -830,11 +828,11 @@ void McR_ShowOneMchResult (void)
       /* Number of questions */
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT_N RIGHT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT_N RIGHT_TOP\"");
       fprintf (Gbl.F.Out,"%s:",Txt_Questions);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT LEFT_TOP\"");
       fprintf (Gbl.F.Out,"%u (%u %s)",
 	       NumQsts,NumQstsNotBlank,Txt_non_blank_QUESTIONS);
       Tbl_EndCell ();
@@ -844,11 +842,11 @@ void McR_ShowOneMchResult (void)
       /* Score */
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT_N RIGHT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT_N RIGHT_TOP\"");
       fprintf (Gbl.F.Out,"%s:",Txt_Score);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT LEFT_TOP\"");
       if (ICanViewScore)
 	 fprintf (Gbl.F.Out,"%.2lf (%.2lf",
 		  TotalScore,
@@ -865,11 +863,11 @@ void McR_ShowOneMchResult (void)
       /* Tags present in this result */
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT_N RIGHT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT_N RIGHT_TOP\"");
       fprintf (Gbl.F.Out,"%s:",Txt_Tags);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_TOP\">");
+      Tbl_StartCellAttr ("class=\"DAT LEFT_TOP\"");
       Gam_ShowTstTagsPresentInAGame (Match.GamCod);
       Tbl_EndCell ();
 
diff --git a/swad_message.c b/swad_message.c
index ff44e5263..0adb6544f 100644
--- a/swad_message.c
+++ b/swad_message.c
@@ -292,11 +292,11 @@ static void Msg_PutFormMsgUsrs (char Content[Cns_MAX_BYTES_LONG_TEXT + 1])
    /***** "To:" section (recipients) *****/
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"%s RIGHT_TOP\">",The_ClassFormInBox[Gbl.Prefs.Theme]);
+   Tbl_StartCellAttr ("class=\"%s RIGHT_TOP\"",The_ClassFormInBox[Gbl.Prefs.Theme]);
    fprintf (Gbl.F.Out,"%s:",Txt_MSG_To);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP\">");
+   Tbl_StartCellAttr ("class=\"LEFT_TOP\"");
    if (Gbl.Msg.ShowOnlyOneRecipient)
       /***** Show only one user as recipient *****/
       Msg_ShowOneUniqueRecipient ();
@@ -495,9 +495,9 @@ static void Msg_WriteFormUsrsIDsOrNicksOtherRecipients (void)
    Tbl_StartRow ();
 
    if (Colspan > 1)
-      fprintf (Gbl.F.Out,"<td colspan=\"%u\" class=\"LEFT_MIDDLE\">",Colspan);
+      Tbl_StartCellAttr ("colspan=\"%u\" class=\"LEFT_MIDDLE\"",Colspan);
    else
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<textarea id=\"OtherRecipients\" name=\"OtherRecipients\""
 	              " class=\"MSG_RECIPIENTS\" rows=\"2\""
 	              " placeholder=\"%s\">",
@@ -537,7 +537,7 @@ static void Msg_WriteFormSubjectAndContentMsgToUsrs (char Content[Cns_MAX_BYTES_
    /***** Message subject *****/
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP\">");
+   Tbl_StartCellAttr ("class=\"RIGHT_TOP\"");
    fprintf (Gbl.F.Out,"<label for=\"MsgSubject\" class=\"%s\">"
 	              "%s:"
 	              "</label>",
@@ -545,7 +545,7 @@ static void Msg_WriteFormSubjectAndContentMsgToUsrs (char Content[Cns_MAX_BYTES_
             Txt_MSG_Subject);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<textarea id=\"MsgSubject\" name=\"Subject\""
                       " class=\"MSG_SUBJECT\" rows=\"2\">");
 
@@ -590,14 +590,14 @@ static void Msg_WriteFormSubjectAndContentMsgToUsrs (char Content[Cns_MAX_BYTES_
       /***** Message content *****/
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP\">");
+      Tbl_StartCellAttr ("class=\"RIGHT_TOP\"");
       fprintf (Gbl.F.Out,"<label for=\"MsgContent\" class=\"%s\">"
 	                 "%s:"
 	                 "</label>",
                The_ClassFormInBox[Gbl.Prefs.Theme],Txt_MSG_Content);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<textarea id=\"MsgContent\" name=\"Content\""
                          " class=\"MSG_CONTENT\" rows=\"20\">");
 
@@ -625,7 +625,7 @@ static void Msg_WriteFormSubjectAndContentMsgToUsrs (char Content[Cns_MAX_BYTES_
       /***** Message content *****/
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP\">");
+      Tbl_StartCellAttr ("class=\"RIGHT_TOP\"");
       fprintf (Gbl.F.Out,"<label for=\"MsgContent\" class=\"%s\">"
 	                 "%s:"
 	                 "</label>",
@@ -633,7 +633,7 @@ static void Msg_WriteFormSubjectAndContentMsgToUsrs (char Content[Cns_MAX_BYTES_
                Txt_MSG_Content);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<textarea id=\"MsgContent\" name=\"Content\""
                          " class=\"MSG_CONTENT\" rows=\"20\">");
 
@@ -2659,7 +2659,7 @@ void Msg_ShowFormToFilterMsgs (void)
    Tbl_StartRow ();
 
    /***** Filter authors/recipients *****/
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label class=\"%s\">"
                       "%s:&nbsp;"
                       "<input type=\"search\" name=\"FilterFromTo\""
@@ -2671,7 +2671,7 @@ void Msg_ShowFormToFilterMsgs (void)
    Tbl_EndCell ();
 
    /***** Filter message content *****/
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label class=\"%s\">"
                       "%s:&nbsp;"
                       "<input type=\"search\" name=\"FilterContent\""
@@ -2967,10 +2967,10 @@ static void Msg_ShowASentOrReceivedMessage (long MsgNum,long MsgCod)
 
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"CONTEXT_COL %s\">",
-            Gbl.Msg.TypeOfMessages == Msg_MESSAGES_RECEIVED ? (Open ? "BG_MSG_BLUE" :
-        	                                                      "BG_MSG_GREEN") :
-                                                              "BG_MSG_BLUE");
+   Tbl_StartCellAttr ("class=\"CONTEXT_COL %s\"",
+		      Gbl.Msg.TypeOfMessages == Msg_MESSAGES_RECEIVED ? (Open ? "BG_MSG_BLUE" :
+									        "BG_MSG_GREEN") :
+								        "BG_MSG_BLUE");
    fprintf (Gbl.F.Out,"<img src=\"%s/%s\""
                       " alt=\"%s\" title=\"%s\""
                       " class=\"ICO16x16\" />",
@@ -2994,9 +2994,8 @@ static void Msg_ShowASentOrReceivedMessage (long MsgNum,long MsgCod)
    /***** Write message author *****/
    Usr_ChkUsrCodAndGetAllUsrDataFromUsrCod (&UsrDat,Usr_DONT_GET_PREFS);
 
-   fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\">",
-            Open ? "MSG_AUT_BG" :
-	           "MSG_AUT_BG_NEW");
+   Tbl_StartCellAttr ("class=\"%s LEFT_TOP\"",Open ? "MSG_AUT_BG" :
+			                             "MSG_AUT_BG_NEW");
    Msg_WriteMsgAuthor (&UsrDat,true,NULL);
    Tbl_EndCell ();
 
@@ -3013,19 +3012,19 @@ static void Msg_ShowASentOrReceivedMessage (long MsgNum,long MsgCod)
      {
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td rowspan=\"3\" colspan=\"2\" class=\"LEFT_TOP\">");
+      Tbl_StartCellAttr ("rowspan=\"3\" colspan=\"2\" class=\"LEFT_TOP\"");
       Tbl_StartTablePadding (2);
 
       /***** Write course origin of message *****/
       Tbl_StartRow ();
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
       FromThisCrs = Msg_WriteCrsOrgMsg (CrsCod);
       Tbl_EndCell ();
       Tbl_EndRow ();
 
       /***** Form to reply message *****/
       Tbl_StartRow ();
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
       if (Gbl.Msg.TypeOfMessages == Msg_MESSAGES_RECEIVED &&
 	  Gbl.Usrs.Me.Role.Logged >= Rol_USR)
 	 // Guests (users without courses) can read messages but not reply them
@@ -3037,11 +3036,11 @@ static void Msg_ShowASentOrReceivedMessage (long MsgNum,long MsgCod)
       Tbl_EndCell ();
 
       /***** Write "From:" *****/
-      fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP MSG_TIT\">");
+      Tbl_StartCellAttr ("class=\"RIGHT_TOP MSG_TIT\"");
       fprintf (Gbl.F.Out,"%s:&nbsp;",Txt_MSG_From);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td colspan=\"2\" class=\"LEFT_TOP\">");
+      Tbl_StartCellAttr ("colspan=\"2\" class=\"LEFT_TOP\"");
       Msg_WriteMsgFrom (&UsrDat,Deleted);
       Tbl_EndCell ();
 
@@ -3050,20 +3049,20 @@ static void Msg_ShowASentOrReceivedMessage (long MsgNum,long MsgCod)
       /***** Write "To:" *****/
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP MSG_TIT\">");
+      Tbl_StartCellAttr ("class=\"RIGHT_TOP MSG_TIT\"");
       fprintf (Gbl.F.Out,"%s:&nbsp;",Txt_MSG_To);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td colspan=\"2\" class=\"LEFT_TOP\">");
+      Tbl_StartCellAttr ("colspan=\"2\" class=\"LEFT_TOP\"");
       Msg_WriteMsgTo (MsgCod);
       Tbl_EndCell ();
 
       Tbl_EndRow ();
 
-      /***** Write "Content:" *****/
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"RIGHT_TOP MSG_TIT\">");
+      /***** Write "Content:" *****/
+      Tbl_StartCellAttr ("class=\"RIGHT_TOP MSG_TIT\"");
       fprintf (Gbl.F.Out,"%s:&nbsp;",Txt_MSG_Content);
       Tbl_EndCell ();
 
@@ -3074,11 +3073,12 @@ static void Msg_ShowASentOrReceivedMessage (long MsgNum,long MsgCod)
       Msg_GetMsgContent (MsgCod,Content,&Media);
 
       /***** Show content and image *****/
-      fprintf (Gbl.F.Out,"<td colspan=\"2\" class=\"MSG_TXT LEFT_TOP\">");
+      Tbl_StartCellAttr ("colspan=\"2\" class=\"MSG_TXT LEFT_TOP\"");
       if (Content[0])
          Msg_WriteMsgContent (Content,Cns_MAX_BYTES_LONG_TEXT,true,false);
       Med_ShowMedia (&Media,"MSG_IMG_CONTAINER","MSG_IMG");
       Tbl_EndCell ();
+
       Tbl_EndRow ();
 
       /***** Free image *****/
@@ -3147,9 +3147,9 @@ void Msg_GetNotifMessage (char SummaryStr[Ntf_MAX_BYTES_SUMMARY + 1],
 
 void Msg_WriteMsgNumber (unsigned long MsgNum,bool NewMsg)
   {
-   fprintf (Gbl.F.Out,"<td class=\"%s CENTER_TOP\" style=\"width:45px;\">",
-	    NewMsg ? "MSG_TIT_BG_NEW" :
-		     "MSG_TIT_BG");
+   Tbl_StartCellAttr ("class=\"%s CENTER_TOP\" style=\"width:45px;\"",
+		      NewMsg ? "MSG_TIT_BG_NEW" :
+			       "MSG_TIT_BG");
    fprintf (Gbl.F.Out,"%lu:",MsgNum);
    Tbl_EndCell ();
   }
@@ -3165,9 +3165,8 @@ static void Msg_WriteSentOrReceivedMsgSubject (long MsgCod,const char *Subject,b
    extern const char *Txt_no_subject;
 
    /***** Start cell *****/
-   fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\">",
-            Open ? "MSG_TIT_BG" :
-        	   "MSG_TIT_BG_NEW");
+   Tbl_StartCellAttr ("class=\"%s LEFT_TOP\"",Open ? "MSG_TIT_BG" :
+        	                                     "MSG_TIT_BG_NEW");
 
    /***** Start form to expand/contract the message *****/
    Frm_StartForm (Gbl.Msg.TypeOfMessages == Msg_MESSAGES_RECEIVED ? (Expanded ? ActConRcvMsg :
@@ -3210,12 +3209,13 @@ void Msg_WriteMsgAuthor (struct UsrData *UsrDat,bool Enabled,const char *BgColor
    /***** Start table *****/
    Tbl_StartTablePadding (2);
 
-   /***** Start first column *****/
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td class=\"CENTER_TOP");
+
+   /***** Start first column *****/
    if (BgColor)
-      fprintf (Gbl.F.Out," %s",BgColor);
-   fprintf (Gbl.F.Out,"\" style=\"width:30px;\">");
+      Tbl_StartCellAttr ("class=\"CENTER_TOP %s\" style=\"width:30px;\"",BgColor);
+   else
+      Tbl_StartCellAttr ("class=\"CENTER_TOP\" style=\"width:30px;\"");
 
    /***** Write author name or don't write it? *****/
    if (Enabled)
@@ -3232,11 +3232,11 @@ void Msg_WriteMsgAuthor (struct UsrData *UsrDat,bool Enabled,const char *BgColor
       Tbl_EndCell ();
 
       /***** Second column with user name (if author has a web page, put a link to it) *****/
-      fprintf (Gbl.F.Out,"<td class=\"LEFT_TOP");
       if (BgColor)
-         fprintf (Gbl.F.Out," %s",BgColor);
-      fprintf (Gbl.F.Out,"\">"
-                         "<div class=\"AUTHOR_2_LINES\">");	// Limited width
+	 Tbl_StartCellAttr ("class=\"LEFT_TOP %s\"",BgColor);
+      else
+	 Tbl_StartCellAttr ("class=\"LEFT_TOP\"");
+      fprintf (Gbl.F.Out,"<div class=\"AUTHOR_2_LINES\">");	// Limited width
       Usr_WriteFirstNameBRSurnames (UsrDat);
       fprintf (Gbl.F.Out,"</div>");
      }
@@ -3251,9 +3251,9 @@ void Msg_WriteMsgAuthor (struct UsrData *UsrDat,bool Enabled,const char *BgColor
       Tbl_EndCell ();
 
       if (BgColor)
-         fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE %s\">",BgColor);
+         Tbl_StartCellAttr ("class=\"LEFT_MIDDLE %s\"",BgColor);
       else
-	 fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+	 Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
      }
 
    /***** End second column *****/
@@ -3371,7 +3371,7 @@ static void Msg_WriteMsgFrom (struct UsrData *UsrDat,bool Deleted)
    Tbl_StartRow ();
 
    /***** Put an icon to show if user has read the message *****/
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\" style=\"width:20px;\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\" style=\"width:20px;\"");
    fprintf (Gbl.F.Out,"<img src=\"%s/%s\""
                       " alt=\"%s\" title=\"%s\""
                       " class=\"ICO16x16\" />",
@@ -3385,7 +3385,7 @@ static void Msg_WriteMsgFrom (struct UsrData *UsrDat,bool Deleted)
    Tbl_EndCell ();
 
    /***** Put user's photo *****/
-   fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\" style=\"width:30px;\">");
+   Tbl_StartCellAttr ("class=\"CENTER_MIDDLE\" style=\"width:30px;\"");
    ShowPhoto = (Pho_ShowingUsrPhotoIsAllowed (UsrDat,PhotoURL));
    Pho_ShowUsrPhoto (UsrDat,ShowPhoto ? PhotoURL :
                 	                NULL,
@@ -3393,7 +3393,7 @@ static void Msg_WriteMsgFrom (struct UsrData *UsrDat,bool Deleted)
    Tbl_EndCell ();
 
    /***** Write user's name *****/
-   fprintf (Gbl.F.Out,"<td class=\"AUTHOR_TXT LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"AUTHOR_TXT LEFT_MIDDLE\"");
    if (UsrDat->UsrCod > 0)
      {
       fprintf (Gbl.F.Out,"%s",UsrDat->FullName);
@@ -3534,7 +3534,7 @@ static void Msg_WriteMsgTo (long MsgCod)
                                         Txt_MSG_Unopened);
          Tbl_StartRow ();
 
-         fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\" style=\"width:20px;\">");
+         Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\" style=\"width:20px;\"");
          fprintf (Gbl.F.Out,"<img src=\"%s/%s\" alt=\"%s\" title=\"%s\""
                             " class=\"ICO16x16\" />",
                   Cfg_URL_ICON_PUBLIC,
@@ -3546,7 +3546,7 @@ static void Msg_WriteMsgTo (long MsgCod)
          Tbl_EndCell ();
 
          /* Put user's photo */
-         fprintf (Gbl.F.Out,"<td class=\"CENTER_TOP\" style=\"width:30px;\">");
+         Tbl_StartCellAttr ("class=\"CENTER_TOP\" style=\"width:30px;\"");
          ShowPhoto = (UsrValid ? Pho_ShowingUsrPhotoIsAllowed (&UsrDat,PhotoURL) :
                                  false);
          Pho_ShowUsrPhoto (&UsrDat,ShowPhoto ? PhotoURL :
@@ -3555,9 +3555,8 @@ static void Msg_WriteMsgTo (long MsgCod)
          Tbl_EndCell ();
 
          /* Write user's name */
-         fprintf (Gbl.F.Out,"<td class=\"%s LEFT_MIDDLE\">",
-                  OpenByDst ? "AUTHOR_TXT" :
-                	      "AUTHOR_TXT_NEW");
+         Tbl_StartCellAttr ("class=\"%s LEFT_MIDDLE\"",OpenByDst ? "AUTHOR_TXT" :
+                	                                           "AUTHOR_TXT_NEW");
          if (UsrValid)
             fprintf (Gbl.F.Out,"%s",UsrDat.FullName);
          else
@@ -3573,7 +3572,7 @@ static void Msg_WriteMsgTo (long MsgCod)
          /***** Start form to show all the users *****/
          Tbl_StartRow ();
 
-	 fprintf (Gbl.F.Out,"<td colspan=\"3\" class=\"AUTHOR_TXT LEFT_MIDDLE\">");
+	 Tbl_StartCellAttr ("colspan=\"3\" class=\"AUTHOR_TXT LEFT_MIDDLE\"");
 	 fprintf (Gbl.F.Out,"[%u %s]",
                   NumRecipientsUnknown,
                   (NumRecipientsUnknown == 1) ? Txt_unknown_recipient :
@@ -3589,7 +3588,7 @@ static void Msg_WriteMsgTo (long MsgCod)
          /***** Start form to show all the users *****/
          Tbl_StartRow ();
 
-         fprintf (Gbl.F.Out,"<td colspan=\"3\" class=\"AUTHOR_TXT LEFT_MIDDLE\">");
+         Tbl_StartCellAttr ("colspan=\"3\" class=\"AUTHOR_TXT LEFT_MIDDLE\"");
          Frm_StartForm (ActionSee[Gbl.Msg.TypeOfMessages]);
          Gbl.Msg.MsgCod = MsgCod;	// Message to be expanded with all recipients visible
          Msg_PutHiddenParamsOneMsg ();
@@ -3628,8 +3627,8 @@ void Msg_WriteMsgDate (time_t TimeUTC,const char *ClassBackground)
    UniqueId++;
 
    /***** Start cell *****/
-   fprintf (Gbl.F.Out,"<td id=\"msg_date_%u\" class=\"%s RIGHT_TOP\" style=\"width:106px;\">",
-            UniqueId,ClassBackground);
+   Tbl_StartCellAttr ("id=\"msg_date_%u\" class=\"%s RIGHT_TOP\" style=\"width:106px;\"",
+                      UniqueId,ClassBackground);
 
    /***** Write date and time *****/
    fprintf (Gbl.F.Out,"<script type=\"text/javascript\">"
@@ -3877,7 +3876,7 @@ void Msg_ListBannedUsrs (void)
             Tbl_StartRow ();
 
             /* Put form to unban user */
-            fprintf (Gbl.F.Out,"<td class=\"BM\">");
+            Tbl_StartCellAttr ("class=\"BM\"");
             Frm_StartForm (ActUnbUsrLst);
             Usr_PutParamUsrCodEncrypted (UsrDat.EncryptedUsrCod);
             Ico_PutIconLink ("lock.svg",Txt_Sender_banned_click_to_unban_him);
@@ -3885,7 +3884,7 @@ void Msg_ListBannedUsrs (void)
             Tbl_EndCell ();
 
             /* Show photo */
-            fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\" style=\"width:30px;\">");
+            Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\" style=\"width:30px;\"");
             ShowPhoto = Pho_ShowingUsrPhotoIsAllowed (&UsrDat,PhotoURL);
             Pho_ShowUsrPhoto (&UsrDat,ShowPhoto ? PhotoURL :
                         	                  NULL,
@@ -3893,7 +3892,7 @@ void Msg_ListBannedUsrs (void)
             Tbl_EndCell ();
 
             /* Write user's full name */
-            fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_MIDDLE\">");
+            Tbl_StartCellAttr ("class=\"DAT LEFT_MIDDLE\"");
             fprintf (Gbl.F.Out,"%s",UsrDat.FullName);
             Tbl_EndCell ();
 
diff --git a/swad_network.c b/swad_network.c
index 8dc36b6ea..272fa6758 100644
--- a/swad_network.c
+++ b/swad_network.c
@@ -325,7 +325,7 @@ void Net_ShowFormMyWebsAndSocialNets (void)
       /***** Row for this web / social network *****/
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"REC_C1_BOT LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"REC_C1_BOT LEFT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<label for=\"URL%u\" class=\"%s\">"
 			 "<img src=\"%s/%s\""
 			 " alt=\"%s\" title=\"%s\""
@@ -340,7 +340,7 @@ void Net_ShowFormMyWebsAndSocialNets (void)
 	       Net_WebsAndSocialNetworksTitle[NumURL]);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<input type=\"url\" id=\"URL%u\" name=\"URL%u\""
 			 " maxlength=\"%u\" value=\"%s\""
 		         " class=\"REC_C2_BOT_INPUT\" />",
@@ -594,7 +594,7 @@ void Net_ShowWebAndSocialNetworksStats (void)
 
 	 Tbl_StartRow ();
 
-	 fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_MIDDLE\">");
+	 Tbl_StartCellAttr ("class=\"DAT LEFT_MIDDLE\"");
 	 fprintf (Gbl.F.Out,"<img src=\"%s/%s\""
 			    " alt=\"%s\" title=\"%s\""
                             " class=\"CONTEXT_ICO_16x16\""
@@ -606,11 +606,11 @@ void Net_ShowWebAndSocialNetworksStats (void)
 		  Net_WebsAndSocialNetworksTitle[Web]);
 	 Tbl_EndCell ();
 
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_MIDDLE\">");
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_MIDDLE\"");
 	 fprintf (Gbl.F.Out,"%u",NumUsrs);
 	 Tbl_EndCell ();
 
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_MIDDLE\">");
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_MIDDLE\"");
 	 fprintf (Gbl.F.Out,"%.2f%%",
 		  NumUsrsTotal ? 100.0 * (float) NumUsrs / (float) NumUsrsTotal :
 			         0.0);
diff --git a/swad_nickname.c b/swad_nickname.c
index de7ea8bf8..13a1f43af 100644
--- a/swad_nickname.c
+++ b/swad_nickname.c
@@ -272,7 +272,7 @@ static void Nck_ShowFormChangeUsrNickname (const struct UsrData *UsrDat,bool Its
       if (NumNick == 1)
 	{
 	 /* The first nickname is the current one */
-	 fprintf (Gbl.F.Out,"<td class=\"REC_C1_BOT RIGHT_TOP\">");
+	 Tbl_StartCellAttr ("class=\"REC_C1_BOT RIGHT_TOP\"");
 	 fprintf (Gbl.F.Out,"<label for=\"Nick\" class=\"%s\">"
 			    "%s:"
 			    "</label>",
@@ -280,14 +280,14 @@ static void Nck_ShowFormChangeUsrNickname (const struct UsrData *UsrDat,bool Its
 		  Txt_Current_nickname);
 	 Tbl_EndCell ();
 
-	 fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_TOP USR_ID\">");
+	 Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_TOP USR_ID\"");
 	}
       else	// NumNick >= 2
 	{
 	 if (NumNick == 2)
 	   {
-	    fprintf (Gbl.F.Out,"<td rowspan=\"%u\" class=\"REC_C1_BOT RIGHT_TOP\">",
-		     NumNicks - 1);
+	    Tbl_StartCellAttr ("rowspan=\"%u\" class=\"REC_C1_BOT RIGHT_TOP\"",
+		               NumNicks - 1);
 	    fprintf (Gbl.F.Out,"<label for=\"Nick\" class=\"%s\">"
 			       "%s:"
 			       "</label>",
@@ -296,7 +296,7 @@ static void Nck_ShowFormChangeUsrNickname (const struct UsrData *UsrDat,bool Its
 	    Tbl_EndCell ();
 	   }
 
-	 fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_TOP DAT\">");
+	 Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_TOP DAT\"");
 
 	 /* Form to remove old nickname */
 	 if (ItsMe)
@@ -371,7 +371,7 @@ static void Nck_ShowFormChangeUsrNickname (const struct UsrData *UsrDat,bool Its
    /***** Form to enter new nickname *****/
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"REC_C1_BOT RIGHT_TOP\">");
+   Tbl_StartCellAttr ("class=\"REC_C1_BOT RIGHT_TOP\"");
    fprintf (Gbl.F.Out,"<label for=\"NewNick\" class=\"%s\">"
                       "%s:"
                       "</label>",
@@ -380,7 +380,7 @@ static void Nck_ShowFormChangeUsrNickname (const struct UsrData *UsrDat,bool Its
         	       Txt_Nickname);		// The first nickname
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_TOP DAT\">");
+   Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_TOP DAT\"");
    if (ItsMe)
       Frm_StartFormAnchor (ActChgMyNck,Nck_NICKNAME_SECTION_ID);
    else
diff --git a/swad_notification.c b/swad_notification.c
index f701a85ac..31b25db58 100644
--- a/swad_notification.c
+++ b/swad_notification.c
@@ -493,8 +493,8 @@ void Ntf_ShowMyNotifications (void)
          /***** Write row for this notification *****/
 	 /* Write event icon */
          Tbl_StartRow ();
-         fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\" style=\"width:25px;\">",
-                  ClassBackground);
+
+         Tbl_StartCellAttr ("class=\"%s LEFT_TOP\" style=\"width:25px;\"",ClassBackground);
          if (PutLink)
             PutLink = Ntf_StartFormGoToAction (NotifyEvent,Crs.CrsCod,&UsrDat,Cod);
 
@@ -510,7 +510,7 @@ void Ntf_ShowMyNotifications (void)
          Tbl_EndCell ();
 
          /* Write event type */
-         fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\">",ClassBackground);
+         Tbl_StartCellAttr ("class=\"%s LEFT_TOP\"",ClassBackground);
          if (PutLink)
             PutLink = Ntf_StartFormGoToAction (NotifyEvent,Crs.CrsCod,&UsrDat,Cod);
 
@@ -527,12 +527,12 @@ void Ntf_ShowMyNotifications (void)
          Tbl_EndCell ();
 
          /* Write user (from) */
-	 fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\">",ClassAuthorBg);
+	 Tbl_StartCellAttr ("class=\"%s LEFT_TOP\"",ClassAuthorBg);
 	 Msg_WriteMsgAuthor (&UsrDat,true,NULL);
 	 Tbl_EndCell ();
 
          /* Write location */
-         fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\">",ClassBackground);
+         Tbl_StartCellAttr ("class=\"%s LEFT_TOP\"",ClassBackground);
          if (NotifyEvent == Ntf_EVENT_FORUM_POST_COURSE ||
              NotifyEvent == Ntf_EVENT_FORUM_REPLY)
            {
@@ -587,7 +587,7 @@ void Ntf_ShowMyNotifications (void)
          Msg_WriteMsgDate (DateTimeUTC,ClassBackground);
 
          /* Write status (sent by email / pending to be sent by email) */
-         fprintf (Gbl.F.Out,"<td class=\"%s LEFT_TOP\">",ClassBackground);
+         Tbl_StartCellAttr ("class=\"%s LEFT_TOP\"",ClassBackground);
          fprintf (Gbl.F.Out,"%s",Txt_NOTIFICATION_STATUS[StatusTxt]);
          Tbl_EndCell ();
 
@@ -603,11 +603,10 @@ void Ntf_ShowMyNotifications (void)
 
             Tbl_StartRow ();
 
-            fprintf (Gbl.F.Out,"<td colspan=\"2\">");
+            Tbl_StartCellAttr ("colspan=\"2\"");
             Tbl_EndCell ();
 
-            fprintf (Gbl.F.Out,"<td colspan=\"4\" class=\"DAT LEFT_TOP\""
-                               " style=\"padding-bottom:12px;\">");
+            Tbl_StartCellAttr ("colspan=\"4\" class=\"DAT LEFT_TOP\" style=\"padding-bottom:12px;\"");
             fprintf (Gbl.F.Out,"%s",SummaryStr);
             Tbl_EndCell ();
 
@@ -1962,11 +1961,11 @@ void Ntf_PutFormChangeNotifSentByEMail (void)
      {
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"%s RIGHT_MIDDLE\">",The_ClassFormInBox[Gbl.Prefs.Theme]);
+      Tbl_StartCellAttr ("class=\"%s RIGHT_MIDDLE\"",The_ClassFormInBox[Gbl.Prefs.Theme]);
       fprintf (Gbl.F.Out,"%s:",Txt_NOTIFY_EVENTS_PLURAL[NotifyEvent]);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"CENTER_MIDDLE\"");
       fprintf (Gbl.F.Out,"<input type=\"checkbox\" name=\"%s\" value=\"Y\"",
                Ntf_ParamNotifMeAboutNotifyEvents[NotifyEvent]);
       if ((Gbl.Usrs.Me.UsrDat.NtfEvents.CreateNotif & (1 << NotifyEvent)))
@@ -1974,7 +1973,7 @@ void Ntf_PutFormChangeNotifSentByEMail (void)
       fprintf (Gbl.F.Out," />");
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"CENTER_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"CENTER_MIDDLE\"");
       fprintf (Gbl.F.Out,"<input type=\"checkbox\" name=\"%s\" value=\"Y\"",
                Ntf_ParamEmailMeAboutNotifyEvents[NotifyEvent]);
       if ((Gbl.Usrs.Me.UsrDat.NtfEvents.SendEmail & (1 << NotifyEvent)))
diff --git a/swad_password.c b/swad_password.c
index e23c72148..0246dc688 100644
--- a/swad_password.c
+++ b/swad_password.c
@@ -687,13 +687,13 @@ void Pwd_ShowFormChgMyPwd (void)
      {
       Tbl_StartRow ();
 
-      fprintf (Gbl.F.Out,"<td class=\"REC_C1_BOT RIGHT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"REC_C1_BOT RIGHT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<label for=\"UsrPwd\" class=\"%s\">%s:</label>",
 	       The_ClassFormInBox[Gbl.Prefs.Theme],
 	       Txt_Current_password);
       Tbl_EndCell ();
 
-      fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_MIDDLE\">");
+      Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_MIDDLE\"");
       fprintf (Gbl.F.Out,"<input type=\"password\""
 			 " id=\"UsrPwd\" name=\"UsrPwd\""
 			 " size=\"18\" maxlength=\"%u\""
@@ -706,7 +706,7 @@ void Pwd_ShowFormChgMyPwd (void)
 
    /***** Help message *****/
    Tbl_StartRow ();
-   fprintf (Gbl.F.Out,"<td colspan=\"2\">");
+   Tbl_StartCellAttr ("colspan=\"2\"");
    Ale_ShowAlert (Ale_INFO,Txt_Your_password_must_be_at_least_X_characters_and_can_not_contain_spaces_,
 	          Pwd_MIN_CHARS_PLAIN_PASSWORD);
    Tbl_EndCell ();
@@ -740,13 +740,13 @@ void Pwd_PutFormToGetNewPasswordOnce (void)
    Tbl_StartRow ();
 
    /***** Start form element ****/
-   fprintf (Gbl.F.Out,"<td class=\"RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"Passwd\" class=\"%s\">%s:</label>",
             The_ClassFormInBox[Gbl.Prefs.Theme],
             Txt_Password);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<input type=\"password\" id=\"Passwd\" name=\"Paswd\""
                       " size=\"18\" maxlength=\"%u\" placeholder=\"",
             Pwd_MAX_CHARS_PLAIN_PASSWORD);
@@ -777,21 +777,20 @@ void Pwd_PutFormToGetNewPasswordTwice (void)
    /* Start form element */
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"REC_C1_BOT RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"REC_C1_BOT RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"Paswd1\" class=\"%s\">%s:</label>",
             The_ClassFormInBox[Gbl.Prefs.Theme],
             Txt_New_password);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<input type=\"password\" id=\"Paswd1\" name=\"Paswd1\""
                       " size=\"18\" maxlength=\"%u\""
                       " placeholder=\"",
             Pwd_MAX_CHARS_PLAIN_PASSWORD);
 
    /* Placeholder */
-   fprintf (Gbl.F.Out,Txt_HELP_password,
-	    Pwd_MIN_CHARS_PLAIN_PASSWORD);
+   fprintf (Gbl.F.Out,Txt_HELP_password,Pwd_MIN_CHARS_PLAIN_PASSWORD);
 
    /* End form element */
    fprintf (Gbl.F.Out,"\" required=\"required\" />");
@@ -803,13 +802,13 @@ void Pwd_PutFormToGetNewPasswordTwice (void)
    /* Start form element */
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"REC_C1_BOT RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"REC_C1_BOT RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"Paswd2\" class=\"%s\">%s:</label>",
             The_ClassFormInBox[Gbl.Prefs.Theme],
             Txt_Retype_new_password);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"REC_C2_BOT LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"REC_C2_BOT LEFT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<input type=\"password\" id=\"Paswd2\" name=\"Paswd2\""
                       " size=\"18\" maxlength=\"%u\""
                       " placeholder=\"",
diff --git a/swad_photo.c b/swad_photo.c
index 177b98aa1..c76615c9e 100644
--- a/swad_photo.c
+++ b/swad_photo.c
@@ -897,7 +897,7 @@ static void Pho_UpdatePhoto2 (void)
         NumPhoto < 3;
         NumPhoto++)
      {
-      fprintf (Gbl.F.Out,"<td class=\"DAT CENTER_TOP\" style=\"width:33%%;\">");
+      Tbl_StartCellAttr ("class=\"DAT CENTER_TOP\" style=\"width:33%%;\"");
       fprintf (Gbl.F.Out,"<img src=\"%s/%s_paso%u.jpg\""
                          " alt=\"%s\" title=\"%s\""
                          " style=\"width:%upx; height:%upx;\" />"
@@ -1790,12 +1790,12 @@ static void Pho_PutSelectorForTypeOfAvg (void)
 
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"AvgType\" class=\"%s\">%s:</label>",
 	    The_ClassFormInBox[Gbl.Prefs.Theme],Txt_Average_type);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    Frm_StartForm (ActSeePhoDeg);
    Pho_PutHiddenParamPhotoSize ();
    Pho_PutHiddenParamOrderDegrees ();
@@ -1854,12 +1854,12 @@ static void Pho_PutSelectorForHowComputePhotoSize (void)
 
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"PhotoSize\" class=\"%s\">%s:</label>",
 	    The_ClassFormInBox[Gbl.Prefs.Theme],Txt_Size_of_photos);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    Frm_StartForm (ActSeePhoDeg);
    Pho_PutHiddenParamTypeOfAvg ();
    Pho_PutHiddenParamOrderDegrees ();
@@ -1918,12 +1918,12 @@ static void Pho_PutSelectorForHowOrderDegrees (void)
 
    Tbl_StartRow ();
 
-   fprintf (Gbl.F.Out,"<td class=\"RIGHT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"RIGHT_MIDDLE\"");
    fprintf (Gbl.F.Out,"<label for=\"Order\" class=\"%s\">%s:</label>",
 	    The_ClassFormInBox[Gbl.Prefs.Theme],Txt_Sort_degrees_by);
    Tbl_EndCell ();
 
-   fprintf (Gbl.F.Out,"<td class=\"LEFT_MIDDLE\">");
+   Tbl_StartCellAttr ("class=\"LEFT_MIDDLE\"");
    Frm_StartForm (ActSeePhoDeg);
    Pho_PutHiddenParamTypeOfAvg ();
    Pho_PutHiddenParamPhotoSize ();
@@ -2161,7 +2161,7 @@ static void Pho_ShowOrPrintClassPhotoDegrees (Pho_AvgPhotoSeeOrPrint_t SeeOrPrin
 	      }
 
 	    /***** Show average photo of students belonging to this degree *****/
-	    fprintf (Gbl.F.Out,"<td class=\"CLASSPHOTO CENTER_MIDDLE\">");
+	    Tbl_StartCellAttr ("class=\"CLASSPHOTO CENTER_MIDDLE\"");
 	    Pho_ShowDegreeAvgPhotoAndStat (&Deg,SeeOrPrint,Usr_SEX_ALL,NumStds,NumStdsWithPhoto);
 	    Tbl_EndCell ();
 
@@ -2252,12 +2252,12 @@ static void Pho_ShowOrPrintListDegrees (Pho_AvgPhotoSeeOrPrint_t SeeOrPrint)
 	 Tbl_StartRow ();
 
 	 /***** Show logo and name of this degree *****/
-	 fprintf (Gbl.F.Out,"<td class=\"DAT RIGHT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT RIGHT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
 	 fprintf (Gbl.F.Out,"%u",++NumDegsNotEmpty);
 	 Tbl_EndCell ();
 
 	 /***** Show logo and name of this degree *****/
-	 fprintf (Gbl.F.Out,"<td class=\"DAT LEFT_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+	 Tbl_StartCellAttr ("class=\"DAT LEFT_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
 	 if (SeeOrPrint == Pho_DEGREES_SEE)
 	    Deg_DrawDegreeLogoAndNameWithLink (&Deg,ActSeeDegInf,
 					       "DAT","CENTER_TOP");
@@ -2274,7 +2274,7 @@ static void Pho_ShowOrPrintListDegrees (Pho_AvgPhotoSeeOrPrint_t SeeOrPrint)
 	   {
 	    /***** Show average photo of students belonging to this degree *****/
 	    Pho_GetNumStdsInDegree (Deg.DegCod,Sex,&NumStds,&NumStdsWithPhoto);
-	    fprintf (Gbl.F.Out,"<td class=\"CLASSPHOTO CENTER_MIDDLE COLOR%u\">",Gbl.RowEvenOdd);
+	    Tbl_StartCellAttr ("class=\"CLASSPHOTO CENTER_MIDDLE COLOR%u\"",Gbl.RowEvenOdd);
 	    if (Gbl.Usrs.Listing.WithPhotos)
 	       Pho_ShowDegreeAvgPhotoAndStat (&Deg,SeeOrPrint,Sex,NumStds,NumStdsWithPhoto);
 	    else