Overlapping Movieckips

Hello everybody, I have a problem with an animation I want flash to perform, which i will explane through pictures.

At the start of the movieclip it looks like this

now when i move the mouse over to one half off the picture I want it to expand to this:

This part is easy…the animation runs fluidly, but then the problem arises…when I move the mouse over the other corner ( or any part of the other picture) i want the movie to first return in its original state (this is easy also), but the to let the other picture expand like this:

The problem only is that picture one is on a higher layer then picture two. This had the implication that the animation for picture 2 is in the background, so i never see the animation for picture 2.

Does anyone know how to solve this?

edit: sorry the original pictures were wrong :(…but i’ve fixed it now