Rollover complex button

What I want to achieve is when you mouse over the “liquid-morph” animated button the whole pic to be presented. The button with the morphing shapes is in a mask layer and under it is the masked layer with the pictured to be revealed. I found out that if the “liquid-morph” animated button is NOT a mask it can load the movie (I’ve put, on the over state of the button, a new movie that reveals the whole pic). But I want to be a mask and when I rollover it to load the movie clip that reveals the pic. Any help?