Finding a script on an object

Hi,

I have the following code which works, but I was wondering how it could be modified to find the DamageReceiver script if it was on the parent of the object that the projectile hit.

e.g.

I shoot the spaceship - I can find the script

I shoot the shield - I cannot – but is there a way I could?

 function OnCollisionEnter( collision : Collision )
 {
  // find out where and what we hit
  var contact : ContactPoint = collision.contacts[0];
  var rotation = Quaternion.FromToRotation( Vector3.up, contact.normal );
  // visual effects
  var instantiatedExplosion : GameObject = Instantiate(explosion, contact.point, transform.rotation);
  // tell the other object that they have been hit and how badly
  if (contact.otherCollider.GetComponent(DamageReceiver))
  {
  contact.otherCollider.GetComponent(DamageReceiver).attacked = true;