.onglet { /*Onglet non survolé*/
background: background-color : #FF0000; no-repeat;

display: inline-block;
width: TAILLEpx;
height: TAILLEpx;
cursor: pointer;
}

.actif { /*Onglet survolé*/
background: background-color : #FF0000; no-repeat;
}

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>

<table width="100%" border="0" cellspacing="1" cellpadding="0" align="center">
<tr>
<td valign="bottom">
<!-- BEGIN switch_user_logged_in -->
<span class="gensmall">{LAST_VISIT_DATE}

{CURRENT_TIME}

</span>
<!-- END switch_user_logged_in -->
<div class="nav"><a class="nav" href="{U_INDEX}">{L_INDEX}</a>{NAV_CAT_DESC}</div>
</td>
<td class="gensmall" align="right" valign="bottom">
<!-- BEGIN switch_user_logged_in -->
<a class="gensmall" href="{U_SEARCH_NEW}">{L_SEARCH_NEW}</a>

<a class="gensmall" href="{U_SEARCH_SELF}">{L_SEARCH_SELF}</a>

<!-- END switch_user_logged_in -->
<a class="gensmall" href="{U_SEARCH_UNANSWERED}">{L_SEARCH_UNANSWERED}</a>
</td>
</tr>
</table>


<!-- DEBUT MODIF ONGLETS -->

<script type="text/javascript">
<!--

document.write('<div align="center" style="display:none;" id="conteneur_barre_onglet">
<ul class="conteneur_onglets">
<li onClick="change_cat(1)" class="onglet actif" id="onglet_1">Le Centre</li>
<li onClick="change_cat(2)" class="onglet " id="onglet_2">L'accueil</li>
<li onClick="change_cat(3)" class="onglet " id="onglet_3">Nos travaux & Nos ressources</li>
<li onClick="change_cat(4)" class="onglet " id="onglet_4">L'espace détente </li>
<li onClick="change_cat(5)" class="onglet " id="onglet_5">Le linge sale</li>
</ul></div>');

var compteur_cat = 1;

function change_cat(numero)
{
   if(document.getElementById('categorie_'+numero))
   {
      /* affichage de la bonne categorie */
      $('table[id^=categorie_]').css('display','none');
      $('table[id=categorie_'+numero+']').fadeIn();
      
      /* affichage du bon onglet */
      $('.actif').removeClass("actif");
      $('.onglet[id=onglet_'+numero+']').addClass("actif");
   }
}

function capture_cat()
{
   if(compteur_cat == 1)
   {
      document.write('<table class="forumline" id="categorie_' + compteur_cat + '" >');
   }
   else
   {
      $('#conteneur_barre_onglet').css("display","block");
      document.write('</table><table class="forumline" id="categorie_' + compteur_cat + '" style="display:none;">');
   }
   
   compteur_cat++;
}

//-->
</script>

<!-- BEGIN catrow --><!-- BEGIN tablehead -->

<script type="text/javascript">
<!--
   capture_cat();
//-->
</script>

<!-- FIN MODIF ONGLETS -->


<tr>
<th colspan="{catrow.tablehead.INC_SPAN}" nowrap="nowrap" width="100%" class="secondarytitle"> {catrow.tablehead.L_FORUM} </th>
<th nowrap="nowrap" width="50">{L_TOPICS}</th>
<th nowrap="nowrap" width="50">{L_POSTS}</th>
<th nowrap="nowrap" width="150"><div style="width:150px;">{L_LASTPOST}</div></th>
</tr>
<!-- END tablehead -->
<!-- BEGIN cathead -->
<tr>
<!-- BEGIN inc -->
<td class="{catrow.cathead.inc.INC_CLASS}" width="46"><img src="{SPACER}" height="0" width="46" /></td>
<!-- END inc -->
<td class="{catrow.cathead.CLASS_CAT}" colspan="{catrow.cathead.INC_SPAN}" width="100%">
<h{catrow.cathead.LEVEL} class="hierarchy">
<span class="cattitle">
<a class="cattitle" title="{catrow.cathead.CAT_DESC}" href="{catrow.cathead.U_VIEWCAT}">{catrow.cathead.CAT_TITLE}</a>
</span>
</h{catrow.cathead.LEVEL}>
</td>
<td class="{catrow.cathead.CLASS_ROWPIC}" colspan="3" align="right"> </td>
</tr>
<!-- END cathead -->
<!-- BEGIN forumrow -->
<tr>
<!-- BEGIN inc -->
<td class="{catrow.forumrow.inc.INC_CLASS}" width="46"><img src="{SPACER}" height="0" width="46" alt="." /></td>
<!-- END inc -->
<td class="{catrow.forumrow.INC_CLASS}" align="center" valign="middle">
<img title="{catrow.forumrow.L_FORUM_FOLDER_ALT}" src="{catrow.forumrow.FORUM_FOLDER_IMG}" alt="{catrow.forumrow.L_FORUM_FOLDER_ALT}" />
</td>
<td class="row1 over" colspan="{catrow.forumrow.INC_SPAN}" valign="top" width="100%" height="50">
<h{catrow.forumrow.LEVEL} class="hierarchy">
<span class="forumlink">
<a class="forumlink" href="{catrow.forumrow.U_VIEWFORUM}">{catrow.forumrow.FORUM_NAME}</a>

</span>
</h{catrow.forumrow.LEVEL}>
<span class="genmed">{catrow.forumrow.FORUM_DESC}</span>
<span class="gensmall">
<!-- BEGIN switch_moderators_links -->
{catrow.forumrow.switch_moderators_links.L_MODERATOR}{catrow.forumrow.switch_moderators_links.MODERATORS}
<!-- END switch_moderators_links -->
{catrow.forumrow.L_LINKS}{catrow.forumrow.LINKS}
</span>
</td>
<!-- BEGIN forum_link_no -->
<td class="row3" align="center" valign="middle" height="50">
<span class="gensmall">{catrow.forumrow.TOPICS}</span>
</td>
<td class="row2" align="center" valign="middle" height="50">
<span class="gensmall">{catrow.forumrow.POSTS}</span>
</td>
<td class="row3 over" align="center" valign="middle" height="50">
<span class="gensmall">{catrow.forumrow.LAST_POST}</span>
</td>
<!-- END forum_link_no -->
<!-- BEGIN forum_link -->
<td class="row3" colspan="3" align="center" valign="middle" height="50"><span class="gensmall">{catrow.forumrow.forum_link.HIT_COUNT}</span></td>
<!-- END forum_link -->
</tr>
<!-- END forumrow -->
<!-- BEGIN catfoot -->
<tr>
<!-- BEGIN inc -->
<td class="{catrow.catfoot.inc.INC_CLASS}" width="46"><img src="{SPACER}" height="0" width="46" /></td>
<!-- END inc -->
<td class="spaceRow" colspan="{catrow.catfoot.INC_SPAN}" height="1"><img src="{SPACER}" alt="" height="1" width="1" /></td>
</tr>
<!-- END catfoot -->
<!-- BEGIN tablefoot -->
<img src="{SPACER}" alt="" height="5" width="1" /><!-- END tablefoot --><!-- END catrow -->