//funzioni di gestione delle sessioni

function Get_Cookie(name) {
	   var start = document.cookie.indexOf(name+"=");
	   var len = start+name.length+1;
	   if ((!start) && (name != document.cookie.substring(0,name.length))) return null;
	   if (start == -1) return null;
	   var end = document.cookie.indexOf(";",len);
	   if (end == -1) end = document.cookie.length;
	   return unescape(document.cookie.substring(len,end));
	 }

    function Set_Cookie(name,value,expires,path,domain,secure){
    	var cookieString = name + "=" +escape(value) +
	       ( (expires) ? ";expires=" + expires.toGMTString() : "") +
	       ( (path) ? ";path=" + path : "") +
	       ( (domain) ? ";domain=" + domain : "") +
	       ( (secure) ? ";secure" : "");
	    document.cookie = cookieString;
    }

    function set_session_id(){
	   if (!Get_Cookie('SessionID'))
	       Set_Cookie('SessionID',(Math.random()*100000000000000000),'','/');       
	  }