character controller that follow a target

hi at all. i am new in unity world ;) now i am working to behaviour of enemy in my game. i have to do a enemy (that have a character controller component) that follow a target. for do that i rotate enemy in direction on target with

characterController.LookAt(target.position) and this work great.

but after i have to move enemy in target direction. i tried to do something using function transormDirection but doesn't work following my code:

GameObject target;
float speed;
CharacterController character;
Vector3 direction;

void Start () {
    speed = 0.2F;
    character = GetComponent<CharacterController>();

// Update is called once per frame
void Update () {
   direction = transform.TransformDirection(target.transform.position);

somebody can help me? ;) thanks a lot ;)

Try this in a regular Update function

 var controller : CharacterController = GetComponent(CharacterController);
        var forward = transform.TransformDirection(Vector3.forward);
        controller.SimpleMove(forward * speed);