Damage receiver help!

I need my gun bullets to send damage. Heres my damage receiver script

var hitPoints = 100.0;
var detonationDelay = 0.0;
var explosion : Transform;
var deadReplacement : Rigidbody;

function ApplyDamage (damage : float) {
// We already have less than 0 hitpoints, maybe we got killed already?
if (hitPoints <= 0.0)

hitPoints -= damage;
if (hitPoints <= 0.0) {
	// Start emitting particles
	var emitter : ParticleEmitter = GetComponentInChildren(ParticleEmitter);
	if (emitter)
		emitter.emit = true;

	Invoke("DelayedDetonate", detonationDelay);


function DelayedDetonate () {
BroadcastMessage (“Detonate”);

function Detonate () {
// Destroy ourselves

// Create the explosion
if (explosion)
	Instantiate (explosion, transform.position, transform.rotation);

// If we have a dead barrel then replace ourselves with it!
if (deadReplacement) {
	var dead : Rigidbody = Instantiate(deadReplacement, transform.position, transform.rotation);

	// For better effect we assign the same velocity to the exploded barrel
	dead.rigidbody.velocity = rigidbody.velocity;
	dead.angularVelocity = rigidbody.angularVelocity;

// If there is a particle emitter stop emitting and detach so it doesnt get destroyed
// right away
var emitter : ParticleEmitter = GetComponentInChildren(ParticleEmitter);
if (emitter) {
	emitter.emit = false;
	emitter.transform.parent = null;


// We require the barrel to be a rigidbody, so that it can do nice physics
@script RequireComponent (Rigidbody)

That script its fine! Now this is my shooting script

var prefabBullet:Transform;
var shootForce:float;

function Update()
var instanceBullet = Instantiate(prefabBullet, transform.position, Quaternion.identity);
instanceBullet.rigidbody.AddForce(transform.forward * shootForce);

Now what can i add to my shooting script so it sends damage?

If you add this script to your bullet, and both the bullet and the target have colliders, then the bullet will apply the damage:

var damage : float;

function OnCollisionEnter (other : Collision){
         // Tell the object you hit that it was damaged
         other.collider.gameObject.SendMessage("ApplyDamage", damage, SendMessageOptions.DontRequireReceiver);

I hope that helps!