XML image gallery with thumbnail grid -- help please!

I’ve followed Kirupa’s XML photogallery and thumbnail scroller and it worked great.

However, there is mention of a GRID setup for the thumbnails, but no explanation about how to accomplish it.

Working from the Kirupa tutorial, how can I implement a grid for my thumbnails that, when next it clicked, it loads the next set of thumbnails? It doesn’t need to scroll or anything. I just want to be able to display the thumbnails in grids with the option to flip through multiple grids.

Any help would be greatly appreciated. Trying to jerry rig the gallery from random forum posts has been driving me crazy. Keep in mind that I’m pretty new to all this…