function switchDiv(n) {
   var id;
   var hide = 0;
   switch(n) {
      case 1 : id = "persoprinc"; break;
      case 3 : id = "sevenheroes"; break;
	  case 2 : id = "youngsevenheroes"; break;
      case 4 : id = "fourtrahivrai"; break;
	  case 5 : id = "fourtrahifaux"; break;
      case 6 : id = "threeglo"; break;
      case 7 : id = "fourchev"; break;
	  case 8 : id = "persosec"; break;
      }
   if ( document.getElementById(id).style.display == "block" ) hide = 1;
   document.getElementById('persoprinc').style.display = "none";
   document.getElementById('youngsevenheroes').style.display = "none";
   document.getElementById('sevenheroes').style.display = "none";
   document.getElementById('fourtrahivrai').style.display = "none";
   document.getElementById('fourtrahifaux').style.display = "none";
   document.getElementById('threeglo').style.display = "none";
   document.getElementById('fourchev').style.display = "none";
   document.getElementById('persosec').style.display = "none";
   if ( hide != 1 ) document.getElementById(id).style.display = "block";
   }