Periodic_server_pings.js

var pingTimer = null;

var pingServer = function () {
    //make a background server request to a ping service
    var x = $("<script/>", {src: "/servlet/ping"});
    $("body").append(x);
    x.remove();
};

var resetPingTimer = function () {
    if (pingTimer !== null) {
	clearInterval(pingTimer);
    }
    pingTimer = null;
    pingTimer = setInterval(pingServer, 120000); //2mins
};

var ajaxStopHandler = function() {
    resetPingTimer();
};

$.ajaxStop(ajaxStopHandler);