Swapdepth issue

i have a button with a movie clip in the up state that expands when you rollover.
i can’t figure out the swapdepth issue with it. i am going to be having other thumbs next to it so i need it to expand over the other thumbs when rolled over, not under the other ones.

anyways i uploaded it so hopefully someone can tell me what i am doing wrong here. thanks guys.
I am using FMX by the way