function setupIndex() {
	var imgs = $$('div.bwimg > a > img');
	imgs.each(function(img) {
		var div = img.getParent().getParent();
		var offUrl = img.src.substring(0, img.src.length - 4) + '-off' + img.src.substring(img.src.length-4, img.src.length);
		var background = "transparent url('" + offUrl + "') no-repeat scroll top left";

		var opts = {transition: Fx.Transitions.linear, property: 'opacity', duration: 500};
		var fxFade = img.get('tween', opts);

		img.set('opacity', 0);
		div.setStyle('background', background);
		div.addEvents({
			'mouseover': function(){
				fxFade.start(1);
			},
			'mouseout': function(){
				fxFade.start(0);
			}
		});
	});
}

document.addEvent('domready', setupIndex);