Issue with jquery Dialog

Hi, At first, I'm sorry for my english... I use your theme, but I have an issue. I did a plugin, which use a Jquery Dialog. But the menu hide it. I post you a screenshot : I tried to fix it with : - MoveToTop (but, it broke the jquery code) - z-index .... find nothing This is my code :

        <script type="text/javascript">
		jQuery( document ).ready(function( $ ) { 
			 
		var $j = jQuery.noConflict();
		// increase the default animation speed to exaggerate the effect
		$j.fx.speeds._default = 1000;
		$j(function() {
			$j('#new_inscription_dialog').dialog({
				autoOpen: false,
				show: 'blind',
				width:700,
				hide: 'explode',
				modal: true,
				buttons: {
				Cancel: function() {
					$j(this).dialog('close');
					}
				}
			});
			$j('#new_inscription_button').click(function() {
					$j('#new_inscription_dialog').dialog('open');
					return false;
			});
		});
		}); 
	</script>

If you can help me ! Thanks ! (for your nice theme too !)