When I move and then rotate my direction doesn't change.

When I rotate I keep moving the same direction. Can someone help?

 using UnityEngine;
 using System.Collections;
 
 public class PlayerScript : MonoBehaviour {

  public float moveSpeed = 10;
  public float sprintSpeed = 15;
  public float jumpSpeed = 20;
  public float gravity = 10;
 
  CharacterController controller;
  Vector3 currentMovement;
 
  void Start () {
 
   controller = GetComponent<CharacterController> ();
  }
 
  void Update () {
 
   currentMovement = new Vector3 (Input.GetAxis ("Horizontal") * moveSpeed, currentMovement.y, currentMovement.z);
   currentMovement = new Vector3 (currentMovement.x, currentMovement.y, Input.GetAxis ("Vertical") * moveSpeed);
 
   if (Input.GetButtonDown ("Jump") && controller.isGrounded)
    currentMovement = new Vector3 (currentMovement.x, jumpSpeed, currentMovement.z);
 
   controller.Move (currentMovement * Time.deltaTime);
 
   if (!controller.isGrounded)
    currentMovement -= new Vector3 (0, gravity, 0);
 
   if (Input.GetMouseButton(1))
    transform.Rotate (0, Input.GetAxis("Mouse X") * Time.deltaTime, 0);
 
   currentMovement = transform.rotation * currentMovement;
  }
 }