//Sys.WebForms.PageRequestManager.getInstance().add_initializeRequest(InitializeRequestHandler);
//function InitializeRequestHandler(sender, eventArgs) {
//    $("div#ajaxProgressBg").parent().css("display", "block");    
//}

//Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
//function EndRequestHandler(sender, eventArgs) {
//    $("div#ajaxProgressBg").parent().css("display", "none");
//}