ActionScript 3.0 :: Load The Corresponding Version Of A Bigger Picture?

When I rollover my thumbnails I want it to load the corresponding version of a bigger picture, which is stored in the name property of each thumbnail. This works but the problem is i also want to, when clicked, goto a URL adress. But now the name property already have the path to the big version so I cant put the URL-path there. So how do I make each thumbnail find the "big version" and the url-path?

Code:
//thumbnail picture
thumb_Loader.load(new URLRequest(xmlList[i].attribute("thumb")));
//thumbnail BIG picture
thumb_Loader.name=xmlList[i].attribute("source");