Enlarge Movieclip

Hi,

I have a movie clip (Grass) with central registration and two buttons (ZoomIn & ZoomOut). I am trying to find working code that will allow me to click the ZoomIn button and the Grass movie clip doubles in size (from 700x700 to 1400x1400 pixels). Then by the clicking the ZoomOut button, it goes back to normal size.
Surely this is a very simple piece of code. Does anyone have this to hand? I can't find help on this anywhere. Thank you.

AS 3.0

Martin

Actionscript Code:

on(release){
    grass._xscale = grass._xscale*2;
    grass._yscale = grass._yscale*2;
}

Lovely, thank you!