var runsAjax = true;
function getXmlHttpRequestObject() {
    if (window.XMLHttpRequest) {
        return new XMLHttpRequest;
    } else if (window.ActiveXObject) {
        return new ActiveXObject("Microsoft.XMLHTTP");
    } else {
        self.runsAjax = false;
        alert("Your browser doesn't support the XmlHttpRequest object.  Better upgrade to Firefox.");
    }
}
getXmlHttpRequestObject();