StackOverflow Question [8187658/314763]

HTML

<script src="http://andrewhays.googlecode.com/svn-history/r4/trunk/js/jquery.blockUI.js"></script>
<input type="button" id="Button3" value="click"/>

JavaScript

$(document).ready(function() {
     $(":button").click(function() {
         $.blockUI({ message: '<h1>Just a moment...</h1>'});

     setTimeout(function() {
         $.unblockUI({
             onUnblock: function() { alert('onUnblock'); }
         });
     }, 2000);
   });
});