Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequest);
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequest);

function beginRequest(sender, args) {
    var x = 0;
    var y = $(window).height() - 20; //  - (document.location.href.indexOf("Edicao.aspx") == -1 ? 52 : 20); // returns height of browser viewport

    try
    {
        // show the popup
        $find("mpeUpdateProgress").set_X(x);
        $find("mpeUpdateProgress").set_Y(y);
        $find("mpeUpdateProgress").show();
    }
    catch(e)
    {
        //window.alert(e.message);
    }
}

function endRequest(sender, args) {
    // hide the popup
    $find("mpeUpdateProgress").hide();
}