Controlling time in Actionscript 3.0

Question

I was wondering if there is a way to directly control time in AS 3.0
I have some code such as:
thumb1.addEventListener(MouseEvent.ROLL_OVER, scaleUP)
function scaleUP(e:MouseEvent):void {
thumb1.scaleX = thumb1.scaleY = 1.5
Obviously, this instantly increases the scale of the thumbnail, but I was wondering if I could have it scale up over a period of time (2 - 3 seconds) so that the size increase is more gradual.
Thanks in advance!

Answer 1

without extra files:
import flash.events.Event;
var speed:Number = 5;
thumb1.addEventListener(MouseEvent.ROLL_OVER, scaleUP);
function scaleUP(e:MouseEvent):void
thumb1.removeEventListener(MouseEvent.ROLL_OVER, scaleUP);
addEventListener(Event.ENTER_FRAME,fScale);
function fScale(evt:Event)
thumb1.scaleX+=(1.5-thumb1.scaleX)/speed;
thumb1.scaleY = thumb1.scaleX;
if (Math.abs(1.5 - thumb1.scaleX) < 0.02)
  removeEventListener(Event.ENTER_FRAME,fScale);
  thumb1.scaleY = thumb1.scaleX = 1.5;