ActionScript 2.0 :: Fade In Some Text At A Certain Point In Movie

I'm trying to fade in some text at a certain point in my movie. After reading the tween class tutorial, I grabbed this snipped of code, slightly modified to be:

Code:
import mx.transitions.Tween;
import mx.transitions.easing.*;
var fadeIn:Tween = new Tween(myTextMovieClip, "_alpha", Elastic.easeInOut, 0, 100, 2, true);

Now, when I run my movie this works just fine. But the thing is, I don't want it to run until a button is clicked in the movie, and the movie clip will not be visible until that button is clicked. So how would I have this tween fire off when the button is clicked? How do I connect them?

Code:
myButton_btn.onRelease = function() {
myMovieClip.fadeIn;
}