Apply damage error

var ApplyDamage:float = 100;

function OnCollisionEnter(hit: Collision){
if(hit.gameObject.tag == "enemy"){
Collision.gameObject.SendMessageUpwards("ApplyDamage", Collision, SendMessageOptions.DontRequireReceiver);


i got a error in unity saying Assets/ApplyDamage.js(5,11): BCE0020: An instance of type ‘UnityEngine.Collision’ is required to access non static member ‘gameObject’.
i want it to apply damage to the zombie with the damage reciever script from the fps tutorial.

Collision is class. You should use instance that you declared (in your example that is hit). So: