jQuery/UpdatePanel busy/loading cursor

ajax-loading.js

//  html.ajax-loading { cursor: wait; }

define(['jquery'], function ($) {
    $(function () {
        var $html = $('html');
        var $document = $(document);
        var cssClass = 'ajax-loading';
        var requests = 0;

        function setBusy() {
            if (++requests == 1) {
                $html.addClass(cssClass);
            }
        }

        function setReady() {
            if (--requests == 0) {
                $html.removeClass(cssClass);
            }
        }

        //jQuery ajax hooks
        $document.ajaxStart(setBusy).ajaxStop(setReady);

        //ASP.Net ajax hooks
        if (Sys) {
            var prm = Sys.WebForms.PageRequestManager.getInstance();

            if (prm) {
                prm.add_initializeRequest(setBusy);
                prm.add_endRequest(setReady);
            }
        }
    });
});