window.addEvent('domready', function(){
		$('left_container').getElements('li.menu_item_main').each( function( elem ){
			var list = elem.getElement('ul.menu_sub');
			if (list != null) {
				var myFx = new Fx.Slide(list, {
						duration: 500,
						transition: 'expo:out'
					});
				myFx.hide();
				elem.addEvents({
					'mouseenter' : function(){
						myFx.cancel();
						myFx.slideIn();
					},
					'mouseleave' : function(){
						myFx.cancel();
						myFx.slideOut();
					}
					});
				}
			})
		});