New XML Data for Thumbnail Gallery

Hello everyone! I am trying to load new XML data in to the XML Thumbnail gallery that is explained on this site. When I click on a button, I want to replace the current loaded XML file with a new XML file. I can get Flash to load the new XML file, but I can’t figure out how to replace the thumbails and image once the new XML file is loaded. Anyone have any suggestions.

Thanks!
wm