Score Keeper / Kill Counter Help

Ok My Score Is not Displaying in game it hits all the debug nodes but it does not update the score on the GUI.

Score Keeper Script:

     @script ExecuteInEditMode()
     
     var currentScore : int = 0;
     
     var time : float = 0.0;
     var hitCrosshairTexture : Texture;
     private var alphaHit : float;
     var hitSound : AudioClip;
     
     var mySkin : GUISkin;
     
     var pointsToNextRank : int = 50;
     var rank : int = 0;
     var rankSound : AudioClip;
 
 function Update () {
 
     if (time > 0){ 
         time -= Time.deltaTime;
     }
     alphaHit = time;
 }
 
 function DrawCrosshair(){
     yield WaitForSeconds(0.1);
     time = 1.0;
     audio.PlayOneShot(hitSound, .5);
 }
 
 function addScore(value : int){
     Debug.Log("Score Added?");
     yield WaitForSeconds(0.2);
     currentScore += value;
     
     if(currentScore >= pointsToNextRank){
         rank++;
         PlayAudioClip(rankSound, transform.position, 1.0);    
         pointsToNextRank += currentScore;
     }
 }
 
 function PlayAudioClip (clip : AudioClip, position : Vector3, volume : float) {
     var go = new GameObject ("One shot audio");
     go.transform.position = position;
     var source : AudioSource = go.AddComponent (AudioSource);
     source.clip = clip;
     source.volume = volume;
     source.pitch = Random.Range(0.95,1.05);
     source.Play ();
     Destroy (go, clip.length);
     return source;
 }    
 
 function OnGUI(){
     GUI.skin = mySkin;
     var style1 = mySkin.customStyles[0];
     
     GUI.Label (Rect(40, Screen.height - 80,100,60)," SCORE :");
 
     GUI.Label (Rect(100, Screen.height - 0,11160,0),"" + currentScore, style1);
     
     GUI.Label (Rect(40, Screen.height - 110,100,60)," LVL :");
     GUI.Label (Rect(100, Screen.height - 110,160,60),"" + rank, style1);
     
     GUI.color = Color(1.0, 1.0, 1.0, alphaHit);
     GUI.DrawTexture (Rect ((Screen.width - hitCrosshairTexture.width)/2, (Screen.height - hitCrosshairTexture.height)/2, hitCrosshairTexture.width, hitCrosshairTexture.height), hitCrosshairTexture);
 }    

And Zombie Health Script:

 var maximumHitPoints = 100.0;
 var hitPoints = 100.0;
 var deadReplacement : Rigidbody;
 var GOPos : GameObject;
 private var scoreManager : ScoreManager;
 
 function Start(){
 
     var GO = gameObject.FindWithTag("ScoreManager");
     scoreManager = GO.GetComponent("ScoreManager");
 }
 
 function ApplyDamage (damage : float) {
     if (hitPoints <= 0.0)
         return;
 
     // Apply damage
     hitPoints -= damage;
     scoreManager.DrawCrosshair();
     // Are we dead?
     if (hitPoints <= 0.0)
         Replace(); 
 }
 
 function Replace() {
  
     // If we have a dead barrel then replace ourselves with it!
     if (deadReplacement) {
         var dead : Rigidbody = Instantiate(deadReplacement, GOPos.transform.position, GOPos.transform.rotation);
         scoreManager.addScore(1);
         Debug.Log("SCORED");
         // For better effect we assign the same velocity to the exploded barrel
         dead.rigidbody.velocity = rigidbody.velocity;
         dead.angularVelocity = rigidbody.angularVelocity;
     }
     // Destroy ourselves
     Destroy(gameObject);
 }