So open up the "contentMain" and put this code on each of the thumbnail buttons
Code:
on (release) {
_parent.polaroids_MC.gotoAndStop("pol2");
}
You will of course have to change the frame number or name accordingly, but basically what it does is say look in the parent movieClip (gallery) and find polaroids_MC, then gotoAndStop(#).
Well that was a large file. I might also suggest an improvement while I'm able to peek around.
Embedding this many images directly into the file makes it huge, and means your visitors will have to load a large quantity of data prior to any viewing. If you load portions of the data as needed (load images when called for example) you can reduce the filesize greatly.