function makeRequest(url,id,dati,op) {
        var httpRequest;
        if (window.XMLHttpRequest) { // Mozilla, Safari, ...
            httpRequest = new XMLHttpRequest();
            if (httpRequest.overrideMimeType) {
                httpRequest.overrideMimeType('text/xml');
                // See note below about this line
            }
        } 
        else if (window.ActiveXObject) { // IE
            try {
                httpRequest = new ActiveXObject("Msxml2.XMLHTTP");
                } 
                catch (e) {
                           try {
                                httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
                               } 
                             catch (e) {}
                          }
                                       }

        if (!httpRequest) {
            alert('Giving up :( Cannot create an XMLHTTP instance');
            return false;
        }
        httpRequest.onreadystatechange = function() { alertContents(httpRequest,id,op); };
        httpRequest.open('POST', url, true);
        httpRequest.setRequestHeader("Content-type","application/x-www-form-urlencoded");
        httpRequest.send(dati);

    }

    function alertContents(httpRequest,id,op) {
	if(httpRequest.readyState == 4) {
            if (httpRequest.status == 200) {
				result = httpRequest.responseText;
				var element = document.getElementById(id);
				element.innerHTML = result;
            } /*else {
                alert('There was a problem with the request.');
            }*/
        }
        else {
        	var element = document.getElementById(id);
        	if(op == 1) element.innerHTML = "Caricamento in corso...";
        }
    }