Cant find audio?

How do I set the source of an audio file in js? The following code doesnt seem to find “clip 2”, ive read teh documentation but couldnt find the answer, how should i set up clip 2?

function OnMouseDown () {
	
	

// Play default sound
audio.Play();

// Wait for the audio to have finished
yield WaitForSeconds (audio.clip.length);

// Assign the other clip and play it
audio.clip = clip2;
audio.Play();



}

I already told you.

http://forum.unity3d.com/viewtopic.php?t=18509&highlight=sound

Do you need a video tutorial?