I'm having a problem getting a button to work. I have a movie clip, which has several layers inside it. When you roll over the movie clip, actionscript makes it play and "open." It stops in the middle to reveal a button. The button is keyframed into one of the layers inside the movie clip. My problem is that you can't press that button! Even though the button is the top layer, it can't be clicked. Why not? How can I make this button usable?

In simpler terms, I have a piano lid movie clip, the lid opens when you roll over it, revealing a key underneath. But You can't press the key. Why not?