// http://davidwalsh.name/snook-navigation-mootools

		window.addEvent('domready', function() {
			/* example a:  top down */
			$$('.level_1 a').each(function(el) {
				//fx
				var fx = new Fx.Tween(el,{
					duration: 500,
					link: 'cancel'
				});
				
				//css & events
				el.setStyle('background-position','-20px 35px').addEvents({
					'mouseenter': function(e) {
						e.stop();
						fx.start('background-position','-20px 94px');
					},
					'mouseleave': function(e) {
						e.stop();
						fx.start('background-position','-20px 35px');
					}
				});
			});
		});