Advanced Mouseover Help!

So I have this code.


onClipEvent(enterFrame){
       this.onRollOver = function(){
    this._alpha -= 1;
   }
       this.onRollOut = function(){
    this._alpha += 1;
   }
}

Its wrong, and I know it cause my code wont work.

Any help on how I can do this (WITHOUT MOTION TWEENING)would be great!

//sky