Sys.Application.add_load(ApplicationLoadHandler)

function ApplicationLoadHandler(sender, args) {
    if (!Sys.WebForms.PageRequestManager.getInstance().get_isInAsyncPostBack()) {
        Sys.WebForms.PageRequestManager.getInstance().add_initializeRequest(InitializeRequest);
    }
}

function InitializeRequest(sender, args) {

    var prm = Sys.WebForms.PageRequestManager.getInstance();

    if (prm.get_isInAsyncPostBack()) {

        var item = document.getElementById(args.get_postBackElement().id);
        if ((etrackAsyncDefault == 'exclusive') || ($(item).parents().hasClass('exclusiveAsync')))
            args.set_cancel(true);
    }
    
}

if (typeof (Sys) !== "undefined") Sys.Application.notifyScriptLoaded();