window.addEvent('domready', function(){
	var rolloverRegex = /\.(gif|jpg|png)/i;
	var rolloutRegex = /-over\.(gif|jpg|png)/i;
	var newImg = new Image();

	var swapSrc = function(thisRegex, replaceString){
		this.set('src', this.get('src').replace(thisRegex, replaceString));
	}

	$$('.rollover').each(function(img){
		if (!img.get('tag').test(/(img|input)/i)) {
			img = img.getFirst('img');
			if (!img) return;
		}

		newImg.src = img.get('src').replace(rolloverRegex, '-over.$1');

		img.addEvents({
			mouseenter: swapSrc.bind(img, [rolloverRegex, '-over.$1']),
			mouseleave: swapSrc.bind(img, [rolloutRegex, '.$1'])
		});
	});
});