How to disable diagonal movement?

I am trying to disable diagonal movement in unity 2D but it doesn't work.

In this code, what is problem?

 void Update () {
         if (Input.GetKey (KeyCode.D)) {
             East = true; West = false; South = false; North = false;
             Direction ();
             //xMove = moveSpeed * Time.deltaTime;
             //yMove = 0 * moveSpeed * Time.deltaTime;
             //this.transform.Translate (xMove, yMove, 0);
             //yMove = 0 * moveSpeed * Time.deltaTime;
             //public Vector3 UpWalk=transform.Translate.position(new Vector3(moveSpeed*Time.deltaTime,0.0,0.0));
             animator.Play ("Right_Move");
         } else if (Input.GetKey (KeyCode.A)) {
             East = false; West = true; South = false; North = false;
             Direction ();
             //xMove = -moveSpeed * Time.deltaTime;
             //yMove = 0 * moveSpeed * Time.deltaTime;
             //this.transform.Translate (xMove, yMove, 0);
             //yMove = 0 * moveSpeed * Time.deltaTime;
             //public Vector3 =transform.Translate.position(new Vector3(-moveSpeed*Time.deltaTime,0.0,0.0));
             animator.Play ("Left_Move");
         }
         if (Input.GetKey (KeyCode.W)) {
             East = false; West = false; South = false; North = true;
             Direction ();
             //xMove = 0 * moveSpeed * Time.deltaTime;
             //xMove = 0 * moveSpeed * Time.deltaTime;
             //yMove = moveSpeed * Time.deltaTime;
             //this.transform.Translate (xMove, yMove, 0);
             //transform.Translate.position(new Vector3(0.0,moveSpeed*Time.deltaTime,0.0));
             animator.Play ("Up_Move");
         } else if (Input.GetKey (KeyCode.S)) {
             East = false; West = false; South = true; North = false;
             Direction ();
             //xMove = 0 * moveSpeed * Time.deltaTime;
             //xMove = 0 * moveSpeed * Time.deltaTime;
             //yMove = -moveSpeed * Time.deltaTime;
             //this.transform.Translate (xMove, yMove, 0);
             //transform.Translate.position(new Vector3(0.0,-moveSpeed*Time.deltaTime,0.0));
             animator.Play ("Down_Move");
         }
         /*if (Input.GetKey (KeyCode.A) && Input.GetKey (KeyCode.W) || Input.GetKey (KeyCode.D) && Input.GetKey (KeyCode.W)) {
             animator.Play ("Up_Move");
         } else if (Input.GetKey (KeyCode.A) && Input.GetKey (KeyCode.S) || Input.GetKey (KeyCode.D) && Input.GetKey (KeyCode.S)) {
             animator.Play ("Down_Move");
         }*/
         if (Input.GetKeyUp (KeyCode.D) || Input.GetKeyUp (KeyCode.A) || Input.GetKeyUp (KeyCode.W) || Input.GetKeyUp (KeyCode.S)) {
             xMove = 0 * moveSpeed * Time.deltaTime;
             yMove = 0 * moveSpeed * Time.deltaTime;
             this.transform.Translate (xMove, yMove, 0);
             //transform.Translate.position(new Vector3(0,0,0));
             animator.Play ("Playeridle");
         }
         /*if(Input.GetKey(KeyCode.A)&&Input.GetKey(KeyCode.S)||Input.GetKey(KeyCode.A)&&Input.GetKey(KeyCode.W)||Input.GetKey(KeyCode.D)&&Input.GetKey(KeyCode.S)||
             Input.GetKey(KeyCode.D)&&Input.GetKey(KeyCode.W)){
             //this.transform.Translate (xMove,yMove,0);
             xMove = 0 * moveSpeed * Time.deltaTime;
             yMove = 0 * moveSpeed * Time.deltaTime;
             this.transform.Translate (xMove,yMove,0);
             animator.Play ("PlayerIdle");
         }*/
 
     }
 
     void Direction(){
         if (West == true) {
             xMove = -moveSpeed * Time.deltaTime;
             yMove = 0 * moveSpeed * Time.deltaTime;
             this.transform.Translate (xMove, yMove, 0);
         } else if (East == true) {
             xMove = moveSpeed * Time.deltaTime;
             yMove = 0 * moveSpeed * Time.deltaTime;
             this.transform.Translate (xMove, yMove, 0);
         } else if (South == true) {
             xMove = 0 * moveSpeed * Time.deltaTime;
             yMove = -moveSpeed * Time.deltaTime;
             this.transform.Translate (xMove, yMove, 0);
         } else {
             xMove = 0 * moveSpeed * Time.deltaTime;
             yMove = moveSpeed * Time.deltaTime;
             this.transform.Translate (xMove, yMove, 0);
         }
     }