Scale with easing on movieclip load - question

Hi,
How do I tell a movieclip to scale-up then scale-down, with easing, on load?

So the buttons appear one after another; scaling from 0% to 120% then back to 100%.

I have got a nice rollover scale w/ easing script; but can’t figure out how to do this at load of movieclip.

import mx.transitions.Tween;
import mx.transitions.easing.*;

this.button1.onRollOver = function() {
	//tween clip, property, easing type, initial value, end value, how long, use seconds
	var scalexTween = new Tween(this, "_xscale", Regular.easeOut, this._xscale, 120, 4, false);
	var scaleyTween = new Tween(this, "_yscale", Regular.easeOut, this._yscale, 120, 4, false);
};
this.button1.onRollOut = function() {
	var scalexTween = new Tween(this, "_xscale", Regular.easeOut, this._xscale, 100, 6, false);
	var scaleyTween = new Tween(this, "_yscale", Regular.easeOut, this._yscale, 100, 6, false);
};

Any questions or comments will be much appreciated!