Why am I getting a parsing error?

Hello, and welcome to Unity Answers!

There are two problems with your code:

1. This is javascript rather than c#. Make sure this lives inside a .js file.

2. Your variable declarations were all commented out.

Here's the fixed code. I also cleaned up the tabs a little bit.

 //target to follow 
 var target : Transform;
 
 //Checks his position, used to follow the target 
 var pos : Transform;
 
 //Ray variables (Length... etc.) 
 var rayLength : float = 3;
 
 //Movement, speed etc. 
 var speed : float = 2;
 
 //You can move if he is not being looked at 
 var move : boolean = false;
 
 //I had problems with my model sinking into the floor, adjust this variable if you need it, or remove it function FixedUpdate() { transform.position.y = 2; }
 
 function Update() { //Setting up Raycast variables for simple object avoidance 
     var fwd = transform.TransformDirection (Vector3.forward); 
     var hit : RaycastHit;
 
     //If you are looking at the object...
     if (renderer.isVisible)
     {
         move = false;
     }
 
     //If you are NOT looking at the object...
     if(!renderer.isVisible)
     {
         move = true;
     }
 
     //If you are not looking at the object...
     if(move)
     {
         //Make him look at the target
         transform.LookAt(target);
         //Always follow the target
         pos.position += pos.forward * speed * Time.deltaTime;
     }
 
     //If he is 3 units away from something, move right (Works if you are not looking at the object)
     if (Physics.Raycast (transform.position, fwd, rayLength) && move)
     {
         Debug.Log("Something ahead, moving");
         transform.Translate(Vector3.right * 3 * Time.deltaTime);}
 
      }