AS motion tween question?

1

I got this code from another thread, and changed it into a button event handler.
It 's a motion tween via AS.
Is it possible to have a second button change
it back to it’s original shape?

btn_1.onRelease = function() {
    var hDiff = Math.round(25-this._height);
    var wDiff = Math.round(500-this._width);
    this._width += wDiff/1;
    this._height += hDiff/1;
};

Could anyone help me with this?

thanks,

regards