One more button question

I want to know for future reference how to make change wether parts of a button are recongnized. I will try to explain what I mean further but just so you guys know, one I say button, i mean making a button using a Movie Cilp.

To simplify my question I will give an example. I would like to know how, when my mouse rolls over the Movie Clip(button), the button enlarges. Then when you roll over the new sections of the button that were previously not there, the RollOut effect occurs.

How to I change wether the new section of the enlarged button triggers the RollOut or RollOver effect? Does it have something to do with Registration Points (whatever those are)? If so how do I change thre Registration Points using a Movie Clip (button)?

THANKS I realize I am a Flash noob but It would be VERY helpful if anyone could tell me how to do this. Thanks.

Two things could be used to accomplish what you are asking,

  1. Invisible button placed over the movieclip that tells the movieclip to do the expanding and contracting.
  2. Use hittest to determine if the mouse is still in the area of the old “button” and if it leaves do the rollout effect.

I would go with 2 but 1 is easier if you want something really quick.

Hope that helps,