help!!! with collider!!!

Why collider it detects the bullet but knife not detect help please!

Code (JavaScript):

1.  
2. private var vidaZombie:int;
3. private var DamageBerreta:float;
4. static var ZombieScore: int=10000;
5. private var buy:boolean;
6.  
7. function  Awake () {
8.  
9. vidaZombie=100;
10.  
11. }
12.  
13. function Damage(){
14.  
15. //Berreta
16. if(GameObject.Find("beretta")!=null){
17. DamageBerreta=25;
18. ZombieScore=ZombieScore+10;
19. vidaZombie=vidaZombie-DamageBerreta;}
20.  
21.  
22.  
23.  
24.  
25. //Cuchillo
26. if(GameObject.Find("Knife")!=null){
27. DamageBerreta=150;
28. ZombieScore=ZombieScore+10;
29. vidaZombie=vidaZombie-DamageBerreta;}
30.  
31. }
32.  
33.  
34. function OnCollisionEnter(zombie: Collision){
35. //Health Zombie
36.        if(zombie.gameObject.tag == "bullet-beretta"){
37.            Damage();
38.    
39.         if (vidaZombie<=0){
40.         ZombieScore=ZombieScore+100;
41.         Destroy(gameObject);
42.         }
43.     }
44.    
45. }
46.  
47.  
48.  
49. function Start () {
50.  
51. }
52.  
53. function Update () {
54.  
55.  
56. }
57.  

 

i have a solution my game objcet kinfe didn´t have a rigidbody component with this the colision is dedectet sorry for wasting your time ;D

 

A tip: ZombieScore += 10; is a better way to update a value.

 

thanks