Unity 3D Robot navmesh script step 4

using UnityEngine;
using System.Collections;

public class Robot : MonoBehaviour
{

    Transform target;

    public float seeDistance = 20;
    public float fireRepeatSpeed = 4;
    public float fireProjectileSpeed = 30;

    public Rigidbody projectile;
    public LayerMask rayMask;

    NavMeshAgent agent;
    Animation avatar;
    Transform eyes;
    bool canSeePlayer;
    Vector3 delta;


    // Use this for initialization
    void Start ()
    {
        target = GameObject.FindGameObjectWithTag("Player").transform;
        agent = GetComponent<NavMeshAgent> ();
        avatar = GetComponentInChildren<Animation> ();
        eyes = transform.Find ("Eyes");
        StartCoroutine( Tracking() );
        StartCoroutine( Firing () );
    }

    IEnumerator Firing()
    {
        while (true)
        {
            yield return new WaitForSeconds(fireRepeatSpeed);

            if (canSeePlayer) {
                Fire();
            }
        }
    }



    void Fire()
    {
        Rigidbody newProjectile = (Rigidbody) Instantiate ( projectile, eyes.position, eyes.rotation );
        newProjectile.AddForce( delta.normalized * fireProjectileSpeed , ForceMode.Impulse );
    }




    IEnumerator Tracking ()
    {
        while (true) {
            yield return new WaitForSeconds(1);

            delta = target.position - eyes.position;

            Ray ray = new Ray (eyes.position, delta);
            RaycastHit hit;

            if (Physics.Raycast (ray, out hit, seeDistance, rayMask)) {

                Debug.Log (hit.collider.name);

                if (hit.collider.tag == "Player")
                {
                    agent.SetDestination (target.position);
                    canSeePlayer = true;
                } else {
                    canSeePlayer = false;
                }

            }

        }

    }



    // Update is called once per frame
    void Update ()
    {

        if (agent.velocity.magnitude > 0.1f) {
            avatar.CrossFade ("run");
        } else {
            avatar.CrossFade ("idle");
        }


    }
}