ETeeskiTutorials FPS Problems [ FPS 1.4 ] Setting a Max Walk Speed (flying glitch)

I was copying code from FPS1.4 Setting a Max Walk Speed and in testing section I found out that player still flies after updating "PlayerMovement" script. Anybody know where I made the mistake?
Link to youtube video http://www.youtube.com/watch?v=GddQmaFLZ00
Code:

Code (csharp):

1. #pragma strict
2.  
3. function Start () {
4.  
5. }
6.  
7. var walkAcceleration : float = 5;
8. var cameraObject : GameObject ;
9. var maxWalkSpeed : float = 20;
10. @HideInInspector
11. var horizontalMovement : Vector2;
12.  
13.  
14. function Update ()
15. {
16.     horizontalMovement = Vector2(rigidbody.velocity.x, rigidbody.velocity.z);
17.     if (horizontalMovement.magnitude > maxWalkSpeed)
18.     {
19.         horizontalMovement = horizontalMovement.normalized;
20.         horizontalMovement *= maxWalkSpeed;
21.        
22.     }
23.     rigidbody.velocity.x = horizontalMovement.x;
24.     rigidbody.velocity.y = horizontalMovement.y;
25.    
26.     transform.rotation = Quaternion.Euler(0, cameraObject.GetComponent(MouseLookScript).currentYRotation, 0);
27.     rigidbody.AddRelativeForce(Input.GetAxis("Horizontal") * walkAcceleration, 0, Input.GetAxis("Vertical") * walkAcceleration);
28. }