function JavascriptChecker(url,params){
	this.req=null;
	this.loadXMLDoc = function(url,params){
		var method="GET";
		// Creo l'oggetto XMLHttpRequest
		if (window.XMLHttpRequest){
			this.req=new XMLHttpRequest();
		} else if (window.ActiveXObject){
			this.req=new ActiveXObject("Microsoft.XMLHTTP");
		}
		// Se l'oggetto è stato creato invio la richiesta
		if (this.req){
			try{
			  this.req.open(method,url,true);
			  this.req.send(params);
			}catch (err){
				this.onerror();
			}
		}
	}
	this.onerror = function(){
		alert("error fetching data!"
			+"\n\nreadyState:"+this.req.readyState
			+"\nstatus: "+this.req.status
			+"\nheaders: "+this.req.getAllResponseHeaders());
	}

	this.loadXMLDoc(url,params);

}