function ajaxRequest(url) {
    var xmlHttp;
    try {
        // Firefox, Opera 8.0+, Safari  
        xmlHttp = new XMLHttpRequest();
    }
    catch (e) {
        // Internet Explorer  
        try {
            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e) {
            try {
                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (e) {
                alert("Your browser does not support AJAX!");
                return false;
            }
        }
    }
    xmlHttp.open("GET", url, false);
    xmlHttp.send(null);
    return xmlHttp.responseText;
}