function initAJAX(script, fn)
{
    if (navigator.appName == "Microsoft Internet Explorer") {
        http = new ActiveXObject("Microsoft.XMLHTTP");
    }
    else {
        http = new XMLHttpRequest();
    }
    http.open("GET", script, true);
    eval("http.onreadystatechange = useHttpResponse_" + fn);
    http.send(null);
}