var ajaxbg = $("#background,#progressBar");
ajaxbg.hide();
$(document).ajaxStart(function () {
    ajaxbg.show();
}).ajaxStop(function () {
    ajaxbg.hide();
});
var ajaxbg = $("#background,#progressBar",parent.document);
ajaxbg.hide();
$(parent.document).ajaxStart(function () {
    ajaxbg.show();
}).ajaxStop(function () {
    ajaxbg.hide();
});