help with if(hit.gameObject.tag)

Hey I try to add health at an ennemy

here is my enemy's scrip

   var vie : int = 500;
  
    function OnCollisionEnter (hit : Collision)
 {
        if(hit.gameObject.tag == "bullet")
      {
      vie -= 25;
      Debug.Log (vie);
      if (vie <= 0){
      Destroy(gameObject);
       }
       }
 }

and here's the shot script on my character

 var bullet : Transform;
     var speed = 650;
     var Speed = 10;
     var spawnPoint : Transform;
     var rapidFire = false;
     var counter = 0.0;
     var rateOfFire = 0.25;
     var ennemydeux : Transform;
      
     function Update ()
     {
     CheckClick();
     }
      
     function CheckClick()
     {
     if(Input.GetButtonDown("Fire1") || (rapidFire && Input.GetButton("Fire1")))
     {
     var ray : Ray = Camera.main.ScreenPointToRay (Input.mousePosition);
     var hit : RaycastHit;
     // you can set the 100 to whatever distance you want :P
     if (Physics.Raycast(ray,hit,100))
     {
     var enemy = hit.transform.GetComponent(ennemy);
     if(hit.transform.GetComponent(ennemy))
     {
     transform.LookAt(ennemydeux);
     HandleFiring();
     }
     }
     }
     }
      
     function HandleFiring()
     {
     if(rapidFire)
     {
     counter += Time.deltaTime;
     // I'm going to assume RateOfFireCounter is a variable that you've not shown here? Otherwise this won't do anything for you...
     if(rateOfFire)
     {
     var shotRapid =Instantiate(bullet, spawnPoint.transform.position, Quaternion.identity);
     shotRapid.rigidbody.AddForce(transform.forward * speed);
     shotRapid.transform.LookAt(ennemydeux);
     shotRapid.transform.Translate(Vector3.forward*Speed*Time.deltaTime);
     Destroy((shotRapid.gameObject), 2);
     
     Counter=0;
     }
     }
     else
     {
     var shot = Instantiate(bullet, spawnPoint.transform.position, Quaternion.identity);
     shot.rigidbody.AddForce(transform.forward * speed);
     shot.transform.LookAt(ennemydeux);
     shot.transform.Translate(Vector3.forward*Speed*Time.deltaTime);
     Destroy((shot.gameObject), 2);
     }
     
     

And the problem is, when the bullet hit my enemy, his life stay at 500. When I remove the part of my script: == "bullet" the enemy lose life when anything hit him.