if (!window.XMLHttpRequest) XMLHttpRequest = function() {
    try { return new ActiveXObject("MSXML3.XMLHTTP"); } catch (e) {}
    try { return new ActiveXObject("MSXML2.XMLHTTP.3.0"); } catch (e) {}
    try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) {}
    try { return new ActiveXObject("Microsoft.XMLHTTP") } catch (e) {}
    return false;
};

function doAjaxCall(url, vars, callbackFunction) {
    var request = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("MSXML2.XMLHTTP.3.0");
    request.open("POST", url, true);
    request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    request.onreadystatechange = function() {
        if (request.readyState == 4 && request.status == 200) {
            if (request.responseText) {
                callbackFunction(request.responseText);
            }
        }
    };
    request.send(vars);
}