my sccripts/Health.js(26,26): BCE0019: 'Damage' is not a member of 'Bullet'.

i don't why but i get a my "sccripts/Health.js(26,26): BCE0019: 'Damage' is not a member of 'Bullet'." here is my script

 #pragma strict
 
 var Health : int = 100;
 var damage : int ;
 var bullet : GameObject;
 function Update () 
 {
    if(Health < 0)
    {
      DIE();
    }
 }
 
 function OnTriggerEnter (hit : Collider ) 
 {
    if(hit.gameObject.tag == "Bullet")
    {
       bullet = hit.gameObject;
       TakeDamage ();
    }
 }
 
 function TakeDamage ()
 {
    var BulletScript : Bullet =  bullet.GetComponent("Bullet");
    damage = BulletScript.Damage;
    
    Health -= damage;
 }
 function DIE ()
 {
   Debug.Log("I'm death");
   Destroy(gameObject);
 }

please help me i don't even understand the error =(