My Enemy isn't moving!

I am a student working on a simple game where the enemy gets closer to you when you're not looking at it. The code so far is making the enemy turn and and face the player when the player looks away and back at the enemy, but he's not moving. This is the entire script. Any help would be appreciated!

 enter code here

var LookAtTarget:Transform;

function Update() { }

function OnBecameVisible () { print("HECANSEEME"); transform.Translate (0,0,0*Time.deltaTime); }

function OnBecameInvisible () { print("IMCOMING!"); transform.LookAt (LookAtTarget); transform.Translate (0,0,20*Time.deltaTime); }