Event.observe 
(
 	window,
	'load',
	function ()
	{
		var menuItems = $$ ('.video-thumbnail');
		
		menuItems.each
		(
		 	function (item)
			{
				Event.observe 
				(
					item,
					'mouseover',
					function ()
					{
						Element.addClassName (item, 'hover');
					}
				);
				
				Event.observe 
				(
					item,
					'mouseout',
					function ()
					{
						Element.removeClassName (item, 'hover');
					}
				);
			}
		);
	}
);