Creating A Vertical Scale & Flip Tween

How to create a vertical scale & flip tween with actionscript:

• Create a movie clip and place it on stage (in the first frame of the main timeline).
• Click on the first keyframe in the main timeline then open the "Actions" panel.
• Enter this code in the "Actions-Frame" panel.
  

onClipEvent(enterFrame){
this._yscale += -5;
}

• Press Ctrl + Enter to test the movie.