boolean flag problem

Hello,

I make a game where the player is supposed to click thing to get points, but only one click per object. I tried this code, but it doesn't work, and the player keeps getting points if clicks on the same object.

Any help?

 function OnMouseDown () {
     var hitted : boolean;
     if(!hitted)
     {
         var score : ScoreCounter = GameObject.Find("Score").GetComponent("ScoreCounter");
         score.scorePoints ++;
         hitted = true;
     }
 }