//a javascript that calls server side log servlet to log
//a request asynchronizely via Ajax call.
function logRequest() {
    var http_request = false;

    if (window.XMLHttpRequest) { // Mozilla, Safari, ...
        http_request = new XMLHttpRequest();
        if (http_request.overrideMimeType) {
            http_request.overrideMimeType('text/xml');
        }
    } else if (window.ActiveXObject) { // IE
        try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                http_request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
        }
    }

    if (!http_request) {
        //Giving up: Cannot create an XMLHTTP instance
        return false;
    }

    url = 'url=' + escape(window.location);
    //alert(url);
    referrer = 'referer=' + escape(document.referrer);
    parameters = url + '%26' + referrer;
    http_request.onreadystatechange = function() { readyFunc(http_request); };
    http_request.open('POST', '/sp/rLog', true);
    http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http_request.setRequestHeader("Content-length", parameters.length);
    http_request.setRequestHeader("Connection", "close");
    http_request.send(parameters);
}

function readyFunc(http_request) {
    //This function is called when server responses from Ajax call.
    //Add any extra handling here if needed on client side.
}