//javascript per il menu espandibile con massimo un livello aperto
var prev= null; 

window.onload=function() { 
if(document.getElementsByTagName && document.getElementById){ 
 // MENU 1
 document.getElementById("nav").className="jsenable"; 
 BuildList('nav');
 // MENU 2
 document.getElementById("nav2").className="jsenable";  
 BuildList('nav2'); 
 } 
} 

function BuildList(idDiv){ 
 var hs=document.getElementById(idDiv).getElementsByTagName("h3"); 
 for(var i=0;i<hs.length;i++){ 
  hs[i].onclick=function(){ 
  if(this.parentNode.className!="show"){ 
   this.parentNode.className="show"; 
   if(prev && prev!=this.parentNode) prev.className="hide"; 
    prev=this.parentNode; 
   } else this.parentNode.className="hide"; 
  } 
 } 
}