function is_array(variable) {
   var source = variable.toSource();
   return (source.search(/^\[([^,]*,)+[^,]*\]/) != -1);
}

function affiche(choix,afermer)
{
     for ( var a=0 ; a<afermer.length ; a++ )
     {
          document.getElementById(afermer[a]).className = "close";
     }

     i = choix.selectedIndex;
     valeur = choix.options[i].value;
     if ( valeur != "" ) document.getElementById(valeur).className = "open";
}

function changeAffichage(id)
{
     if ( is_array(id) )
     {
          for ( var i=0 ; i<id.length ; i++ )
          {
               if ( document.getElementById(id[i]).className == "close" )
               {
                    document.getElementById(id[i]).className = "open";
               }
               else
               {
                    document.getElementById(id[i]).className = "close";
               }
          }
     }
     else
     {
          if ( document.getElementById(id).className == "close" )
          {
               document.getElementById(id).className = "open";
          }
          else
          {
               document.getElementById(id).className = "close";
          }
     }

     return false;
}