Animation won't start when collision starts

I am reading "Unity 3.x game development essentials" and i am blocked at "adding the coconut shy shack" paragraph. I wrote all the code for make the target play an animation when it collides with a coconut, the code is good, but when i instantiate a coconut and it hits the target, the target won't start the animation. This is my code:

 #pragma strict
 private var beenHit:boolean=false;
 private var targetRoot:Animation;
 var hitSound:AudioClip;
 var resetSound:AudioClip;
 var resetTime:float = 3.0f;
 function Start () {
 targetRoot=transform.parent.transform.parent.animation;
 }
 
 function Update () {
 
 }
 function OnCollisionEnter(theObject:Collision){
 if (beenHit==false && theObject.gameObject.name=="Coconut"){
 StartCoroutine("targetHit");
 }
 }
 function targetHit(){
 
 audio.PlayOneShot(hitSound);
 targetRoot.Play("down");
 beenHit=true;
 yield new WaitForSeconds(resetTime);
 audio.PlayOneShot(resetSound);
 targetRoot.Play("up");
 beenHit=false;
 }

this is my scene setting: Image1

And this is my target's animations setting:

Image2