AS Tweening

1

I have a movieclip with the instance name of top.

I want the box to grow from right to left, not left to right.

Here is my code:


top.onEnterFrame = function() {
        var hDiff = Math.round(17-this._height)
var wDiff = Math.round(800-this._width)
        this._width += wDiff/3
        this._height += hDiff/3
}