HELP!!! Sound won't play upon Collision! Script looks correct...

Hi guys, This script below isn't working. I've just spent the last 2 hours trying to get it to work but it just isn't happening. My sound file has been converted to a .ogg file, and everything looks correct to me and I get no compile errors. Anyone see what's wrong?

I need it to play the sound when the player touches the object. I am using the FirstPersonControllerPrefab from IslandDemo.

Thanks in advance

var moon : AudioClip; // set this to your sound in the inspector

function OnCollisionEnter (collision : Collision) {
    // next line requires an AudioSource component on this gameobject
    audio.PlayOneShot(moon);
}

I you are using the FirstPersonController there probably won't be a Collision Event. Try to use OnControllerColliderHit() instead of OnCollisionEnter.

There is a chart that explains which collision events will fire under certain circumstances.

There are actually three categories of "Colliders". Static (no rigidbody attached), Rigidbody , and Kinematic Rigidbody.

The chart explains under which circumstances each of these will fire.

You can view it here: http://unity3d.com/support/documentation/Components/class-BoxCollider.html

Scroll down to the bottom of the page.