Adding renderers to script?

var Distance; var Target : Transform; var Lookatdistance = 25.0; var attacksrange = 15.0; var movespeed = 5.0; var damping = 6.0;

function Update () { Distance = Vector3.Distance(Target.position, transform.position);

  if(Distance < Lookatdistance)
  {
      renderer.material.color = Color.gray;
      Lookat();
  }
  if(Distance > Lookatdistance)
  {
      renderer.material.color = Color.yellow;
  }
  if(Distance < attacksrange)
  {
      renderer.material.color = Color.red;
      attack ();
  }

}

function Lookat() { var rotation = Quaternion.LookRotation(Target.position - transform.position); transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * damping);

}

function attack () { transform.Translate(Vector3.forward movespeed Time.deltaTime); }

private function applyColor(Green : Color) { var renderers: Component[] = GetComponentsInChildren(Renderer); for (var renderer: Renderer in renderers) renderer.material.color = Green; }

Im not sure if the script I used to add the renderer is wrong? it just doesnt seem to work, It's javascript can someone please help?