var http_request = false;

    function makeRequest(url) {

        //url = "test2.asp"
        http_request = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari,...
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {
                http_request.overrideMimeType('text/xml');
            }
        } else if (window.ActiveXObject) { // IE
            try {
                http_request = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    http_request = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {}
            }
        }

        if (!http_request) {
            alert('Giving up :( Cannot create an XMLHTTP instance');
            return false;
        }
        http_request.onreadystatechange = alertContents;
        http_request.open('GET', url, true);
        //let IE refresh page
        http_request.setRequestHeader("If-Modified-Since","0");
        http_request.send(null);
        //alert("Success")

    }
    
    
    
    function alertContents() {

        if (http_request.readyState == 4) {
          //alert("1");
            if (http_request.status == 200) {
                //alert(http_request.responseText);
            } else {
                //alert('There was a problem with the request.');
            }
        }

    }