It is AS3
Here is an example. If you have a movieclip on the stage named "ball", this will do what you claim to want:
import flash.events.Event;
import fl.transitions.Tween;
import fl.transitions.easing.*;
ball.doubleClickEnabled = true;
ball.addEventListener(MouseEvent.DOUBLE_CLICK, doZoom);
function doZoom(e:Event):void {
var _this = e.target;
if (!_this.init) {
_this.init = true;
_this.zoomed = false;
_this.origXS = _this.scaleX;
_this.origYS = _this.scaleY;
}
var zoomScale:Number = 2;
var zoomFrames:Number = 15;
if (!_this.zoomed) {
// zoom
_this.zoomed = true;
new Tween(_this, "scaleX", Strong.easeOut, _this.scaleX, zoomScale, zoomFrames);
new Tween(_this, "scaleY", Strong.easeOut, _this.scaleY, zoomScale, zoomFrames);
}
else {
// unzoom
_this.zoomed = false;
new Tween(_this, "scaleX", Strong.easeOut, zoomScale, _this.origXS, zoomFrames);
new Tween(_this, "scaleY", Strong.easeOut, zoomScale, _this.origYS, zoomFrames);
}
}