Blocking UI while loading Ajax UpdatePanel in ASP.NET

gistfile1.js

//include the jquery.blockui.js plugin on your page first

<script type="text/javascript">
        Page = Sys.WebForms.PageRequestManager.getInstance();
        Page.add_beginRequest(OnBeginRequest);
        Page.add_endRequest(endRequest);

        function OnBeginRequest(sender, args) {
            $.blockUI();
        }
        function endRequest(sender, args) {
            $.unblockUI();
        }
       
 </script>

Fantastically handy bit of code, that! :)