Event.observe (window, 'load', menu, false);

function menu ()
{

	if ($('menu'))
	{
		
		$$('#menu li').each (function (e)
		{
			
			e.addClassName ('under');
			
			Event.observe (e, 'mouseover', function ()
			{
				this.removeClassName ('under');
				this.addClassName ('over');
			});
			
			Event.observe (e, 'mouseout', function ()
			{
				this.removeClassName ('over');
				this.addClassName ('under');
			});
			
		})
		
	}

}