window.addEvent('domready', function(){
	$$('img').each(function(img){
		if (img.getProperty('src').contains('_off')) {
			var image = new Image();
			var element = $(image) || new Element('img');
			image.src = element.src = img.get('src').replace('_off', '_on');
			img.addEvent('mouseenter', function(){
				img.set('src', img.get('src').replace('_off', '_on'));
			}).addEvent('mouseleave', function(){
				img.set('src', img.get('src').replace('_on', '_off'));
			});
		}
	});
});