Problem with pathfinding tutorial

Hi, for anyone that answers thanks! Now i wathced this tutorial: https://www.youtube.com/watch?v=fvdRKS8x0aM and wrote this script. using UnityEngine; using System.Collections;

public class MonsterMotor : MonoBehaviour {

 Transform target;

 public float HP = 100;
 public Transform[] path;
 public float reacheDistance = 1;
 public int curPoint = 0;
 public float speed = 5;
 float DeathTime = 3;

 void Start () {
     target = GameObject.FindGameObjectWithTag ("Player").transform;
 }
 
 // Update is called once per frame
 void Update () 
 {

     Vector3 dir = path [curPoint].position - transform.position;
     transform.position += dir * Time.deltaTime * speed;

     if (dir.magnitude <= reacheDistance) {
         curPoint++;
     }
     if (curPoint >= path.Length) {
         curPoint = 0;
     }
 

     if (HP <= 0) {
         Death ();
     }
 
 }

 void Death () 
 {
     Destroy(gameObject, DeathTime);
 }

 void OnDrawGizmos ()
 {
     if (path.Length > 0) {
         for (int i = 0; i < path.Length; i++) {
             if (path [i] != null) {
                 Gizmos.DrawSphere (path [i].position, reacheDistance);
             
         
             }
     
         }
 
     }

 }

}

But the cube just stops at the first marker. Thanks again for anyone for answering.