Playing MC's on different levels

Right, I’m basically trying to recreate something that will eventually work like this site.

http://www.portable-gallery.com/

The problem I’m having is loading my info boxes. Basically, I want the the info boxes to stay on the middle of the main stage and also make the scroll mc non selectable (so that other mc’s cannot be selected). I’ve been trying for ages to get this working but can’t seem to make the buttons play the relative info box movie clips.

Currently, the info box mc’s are in the same movie clip as the mask & scroll mc. However, the buttons I want to activate the info box mc’s are in the scroll mc. If I put the info boxes in the same mc as the buttons then it works fine but doesn’t keep the info box moie clip in the middle of the stage as you can still scoll/select other itms in the mc.

Does any one know how I can get them to work when they’re on different levels?

Hope that makes sense. If not I can post a flash file for you to take a look at. Thanks in advance.