Following Script Not Working Properly

Hey guys, i have a problem with my script here, the script works but when the enemy follows me it keeps descending with as result going trough the terrain (putting the model higher doesn't work) other then that the script works perfectly fine. Thanks in advance.

The Script:

 #pragma strict
 
 function Start () {
 
 }
 
 //target to follow 
 var target : Transform;
 
 //Checks his position
 var pos : Transform;
 
 //Ray variables
 var rayLength : float = 3;
 
 //Speed
 var speed : float = 4;
 
 //Move
  var move : boolean = false;
 
 function FixedUpdate() {
 
 }
 
 function Update() {
 var fwd = transform.TransformDirection (Vector3.forward); var hit : RaycastHit;
 
 
     if (renderer.isVisible)
     {
     move = false;
     }
 
  
     if(!renderer.isVisible)
     {
     move = true;
     }
 
     //Follows meh i don't watch him
     if(move)
     {
     //Look at target
     transform.LookAt(target);
     //Follow meh
     pos.position += pos.forward * speed * Time.deltaTime;
     }
 
     //Temp avoidance
     if (Physics.Raycast (transform.position, fwd,rayLength)
 && move)
     {
     Debug.Log("Moving.");
     transform.Translate(Vector3.right * 3 * Time.deltaTime);
     }
 
 }