Switching between movies

Hi!!!
Friends.

I want help from you.

In my FLASH document, there is main timeline (parent) which contains 3 movies. MyForeground (child of parent) is one of the movie placed on main timeline.
In MyForeground movie, there is one button & one movie called Movie1 (Child of child movie).
When user enters in MyForeground, he can start Movie1 by clicking button.
But I don’t know, what action script is require to button, so that movie jumps in first frame of Movie1.
So please help me out.