// funzione per assegnare l'oggetto XMLHttpRequest
function assegnaXMLHttpRequest() {
var XHR = null,browserUtente = navigator.userAgent.toUpperCase();

 if(typeof(XMLHttpRequest) === "function" || typeof(XMLHttpRequest) === "object")
  XHR = new XMLHttpRequest();
 else if(window.ActiveXObject && browserUtente.indexOf("MSIE 4") < 0 ){
  if(browserUtente.indexOf("MSIE 5") < 0)
   XHR = new ActiveXObject("Msxml2.XMLHTTP");
  else
   XHR = new ActiveXObject("Microsoft.XMLHTTP");
 }
 return XHR;
}

function sendRequest(URL,postData)
{
	var req =  assegnaXMLHttpRequest();
	if (!req) return;
			req.open('POST',URL,false);
	if (postData)
			req.setRequestHeader('Content-type','application/x-www-form-urlencoded');
					
	req.send(postData);
	return req.responseText;			
}