function createXMLHttpRequest() {
    var req;

    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
       	try {
            req = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (ex) {
            req = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    
    return req;
}