Unity 3D Navesh Agent Control - step 2

using UnityEngine;
using System.Collections;

public class AgentControl : MonoBehaviour {

    public Transform target;
    NavMeshAgent agent;
    float originalSpeed;

    // Use this for initialization
    void Start () {
        agent = GetComponent<NavMeshAgent>();
        originalSpeed = agent.speed;

        StartCoroutine( LookForTarget() );

    }

    IEnumerator LookForTarget()
    {

        while(true)
        {

            Vector3 direction = (target.position+Vector3.up) - transform.position;
            Ray ray = new Ray( transform.position, direction );
            RaycastHit hit;

            Debug.DrawRay( ray.origin, ray.direction*direction.magnitude );

            if ( Physics.Raycast( ray, out hit ) )
            {
                if (hit.collider.tag == "Player")
                {
                    agent.SetDestination( target.position );
                }

                Debug.Log (hit.collider.name);
            }


            yield return new WaitForSeconds(Random.value+0.5f);
        }


    }



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

        int mask = 1 << NavMesh.GetNavMeshLayerFromName("No Running");

        NavMeshHit navHit;
        agent.SamplePathPosition (-1, 0, out navHit);


        if ( (navHit.mask & mask) != 0)
        {
            agent.speed = originalSpeed * 0.3f;

        } else {
            agent.speed = originalSpeed;
        }


    }



}