What is wrong with my code? NullReferenceException

okay so the code is to play a audio clip once the "ball"/player reaches y-10. but now instead of restarting the level at y-10 the ball keeps falling and i get the error message


NullReferenceException: Object reference not set to an instance of an object
BallHealth+$RestartLevel$6+$.MoveNext () (at Assets/Scripts/BallHealth.js:24)
UnityEngine.MonoBehaviour:StartCoroutine_Auto(IEnumerator)
BallHealth:Update() (at Assets/Scripts/BallHealth.js:14)

This is my code:

Code (csharp):

1.  #pragma strict
2.  
3. var maxFallDistance = -10;
4. private var isRestarting = false;
5.  
6. var GameOverSound : AudioClip;
7.  
8. function Update ()
9. {
10.     if (transform.position.y <= maxFallDistance)
11.     {
12.         if (isRestarting == false)
13.         {
14.             RestartLevel();
15.         }
16.     }
17. }
18.  
19. function RestartLevel () {
20.     isRestarting = true;
21.     GetComponent.<AudioSource>().pitch = 1;
22.     GetComponent.<AudioSource>().clip = GameOverSound;
23.     GetComponent.<AudioSource>().Play();
24.     yield WaitForSeconds (GetComponent.<AudioSource>().clip.length);
25.     Application.LoadLevel("Level01");
26. }
27. [\Code]

 

It's either complaining that there isn't an AudioSource component attached to the GameObject, or there is no clip in the AudioSource.