Animation not playing when player moves

Hi guys,
Been trying to get a simple walking animation to play when the player moves around the screen.
Below is the gameobjects attached components inc. an animation and also the script that I've got attached to the player.

Code (CSharp):

1.     void Update ()
2.     {
3.         HandleInput();
4.     }
5.  
6.     void HandleInput()
7.     {
8.         if (Input.GetKey(KeyCode.W))
9.         {
10.             yPos += 0.1f;
11.             animation.Play("WalkingPlayer");
12.         }
13.         if (Input.GetKey(KeyCode.S))
14.         {
15.             yPos -= 0.1f;
16.             animation.Play("WalkingPlayer");
17.         }
18.         if (Input.GetKey(KeyCode.A))
19.         {
20.             xPos -= 0.1f;
21.             animation.Play("WalkingPlayer");
22.         }
23.         if (Input.GetKey(KeyCode.D))
24.         {
25.             xPos+=0.1f;
26.             animation.Play("WalkingPlayer");
27.         }
28.  
29.         CheckPosition();
30.  
31.         newPos = new Vector3(xPos, yPos, 0);
32.         gameObject.transform.position = newPos;
33.        
34.     }
35.  

I've had a look online and can't see any solutions that apply to my issue. Any help would be greatly appreciated!