Simple rollout

I how this site knows i’m there first source for flash help, and…
How do i make a rollout

A rollout as in an action on a button? If so, that would be

<U>Button</U>
on (rollOut){
//your actions here
}

<U>Movie Clip (applied to frame)</U>
_root.yourMC.onRollOut = function(){
//your actions here
}

If not, can you please elaborate?