Scorekeeper.js

var textMesh:TextMesh;
var score = 0;
var scorekeeper : ScoreKeeper;

function Start (){
     scorekeeper = GameObject.FindObjectOfType(ScoreKeeper);
}

function Awake () {
    textMesh = GetComponent(TextMesh);
}

function AddToScore(){
    ++score;
    textMesh.text = "" + score;
}