window.addEvent('domready', function() {
 
	var childs = $('nav').getElements('ul');
	childs.each(function(el) {
		el.setStyle('opacity', 0);
	});
 
	var childs = $('nav').getElements('ul');
	childs.each(function(el) {
 		var elFx = new Fx.Styles(el, {duration: 500, transition: Fx.Transitions.Sine.easeInOut, wait: false});
 
		el.getParent().addEvent('mouseenter', function() {
			el.setStyle('display','block');
			elFx.start({
				'opacity': ['0', '1']
			});
 		});
 
		el.getParent().addEvent('mouseleave', function() {
			elFx.start({
				'opacity': ['1', '0']
			});
 		});
	});
 
});