"Hey folks, in this tutorials I'd like to make the arrows look better by adjusting their position and adding some opacity to make them semi-transparent. By the way, I would recommend you to use Google Chrome as browser for this tutorial series, since the CSS property "opacity" is not supported in old browsers. But if you use an old version Internet Explorer (I feel sorry for you) or something similar, you can ask me for a workaround to make the opacity work."
http://www.mybringback.com/?p=13840