window.addEvent('load', function() 
	{  
	var myListItems = $$('#mainmenu li');
	menu_length = myListItems.length;
	for(i=0;i<menu_length;i++)
		{
		myListItems[i].addEvent('mouseover', function(e)
			{
			if (this.getElement('ul')) {
				this.getElement('ul').style.display = 'block';
			}
			});
		myListItems[i].addEvent('mouseout', function(e)
			{
			if (this.getElement('ul')) {
				this.getElement('ul').style.display = 'none';
			}
			});
		}
	});