BCE0019: 'position' is not a member of 'UnityEngine.GameObject'.

thats what i get and i dont know why? help would be much appreciated!

Code btw:

var enemy: Transform;
var player: GameObject;
var dir: Vector3;
var speed: float;
var observed: boolean;

function update () {
    if(observed) {
        dir = player.position = transform.position;
        dir = dir.normalized;
        transform.Translate(dir * speed, Space.World);
    }
    else {
        transform.eulerAngles.y = Mathf.PingPong(Time.time*20,90) -45;
    }

function OnTriggerEnter (other:Collider) {
    if(player) observed = true; 
}