<script type="text/javascript"> 

    // unblock when ajax activity stops

    $(document).ajaxStop($.unblockUI); 

    function test() {

        $.ajax({ url: 'wait.php', cache: false });

    } 

    $(document).ready(function() {

        $('#pageDemo1').click(function() {

            $.blockUI();

            test();

        });

        $('#pageDemo2').click(function() {

            $.blockUI({ message: '<h1><img src="busy.gif" /> Just a moment...</h1>' });

            test();

        });

        $('#pageDemo3').click(function() {

            $.blockUI({ css: { backgroundColor: '#f00', color: '#fff' } });

            test();

        }); 

        $('#pageDemo4').click(function() {

            $.blockUI({ message: $('#domMessage') });

            test();

        });

    }); 

</script> 

... 

<div id="domMessage" style="display:none;">

    <h1>We are processing your request.  Please be patient.</h1>

</div>