var SelectedMenu = null;

Event.observe(window, 'load', function(){
	$$(".main_items_menu").each(function(item){
		item.observe('mouseover', function(){
			if (SelectedMenu!=null)
			{
				SelectedMenu.setStyle({display: 'none'});
			}
			$$('#'+item.id+'_ul').each(function(item2){

				item2.setStyle({display: 'block'});
				SelectedMenu = item2;
			});
		});
	});
});