laf-jquery-ui-demo

gistfile1.html

<script>
$(function() {
	$( "#dialog-modal" ).dialog({
		height: 140,
		modal: true
	});
});
</script>

<div id="dialog-modal" title="Basic modal dialog">
	<p>
           Adding the modal overlay screen makes 
           the dialog look more prominent because 
           it dims out the page content.
        </p>
</div>