Turret Rotation Not correct

Alright, so I followed this tutorial to learn how to make a turret http://cgcookie.com/unity/lessons/1-autoturret/ And I ended with this code: using UnityEngine; using System.Collections;

 public class EnemyAI : MonoBehaviour {
     public GameObject zero;
     public GameObject one;
     public GameObject firePos;
     public GameObject myTarget;
     public Transform EnemyTur;
     Quaternion desiredRotation;
 
     public float bulletImpulse = 20f;
     public float range = 20f;
     public float turnSpeed = 3f;
 
     public Vector3 target;
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         Debug.Log (myTarget);
         if (myTarget != null) {
             target = myTarget.transform.position;
             CalculateAimPosition(target);
             Debug.Log ("IDK");
             EnemyTur.rotation = Quaternion.Lerp (EnemyTur.rotation, desiredRotation, Time.deltaTime*turnSpeed);
                 }
     }
 
     void Fire(){
         float ranNum;
         ranNum = Random.Range (-1.0f, 1.0f);
         if (ranNum >=0 && ranNum <=1)
         {
             GameObject bullet2 = (GameObject)Instantiate(zero, firePos.transform.position + firePos.transform.forward, firePos.transform.rotation);
             bullet2.rigidbody.AddForce( firePos.transform.forward * bulletImpulse, ForceMode.Impulse);
         }
         else
         {
             GameObject bullet1 = (GameObject)Instantiate(one, firePos.transform.position + firePos.transform.forward, firePos.transform.rotation);
             bullet1.rigidbody.AddForce( firePos.transform.forward * bulletImpulse, ForceMode.Impulse);
         }
     }
     void OnTriggerEnter(Collider tar){
         if (tar.gameObject.tag == ("Player")) {
             myTarget = tar.gameObject;
                 }
     }
     void OnTriggerExit (Collider tar){
         if (tar.gameObject.transform == myTarget) {
             myTarget = null;
             Debug.Log ("Null");
                 }
     }
     void CalculateAimPosition (Vector3 tarf){
         Vector3 aimPoint = new Vector3 (target.x, target.y, target.z);
         desiredRotation = Quaternion.LookRotation (aimPoint);
         Debug.Log ("Position");
 
     }
 
 }

But instead of rotating and facing the player, the turret floats up, rotates and looks at a random point. It follows the player, as in it rotates as I move around, but no in the way it should. It moves when I get close or farther away from it, now when I go around it. Any idea where I messed up? Thanks for your time.