Audio Play/Stop Trouble

Hi, Im having trouble with my sound on my game. i have it where when you hit an invisible wall then music starts to play. but i want music playing before that to stop playing and my new music to start. so basically i need one audio clip to stop and a different one to start at the same time. Thanks for any help!

here's a script from the unity scripting reference. it stops an already playing sound or music file after it's fully done playing, pauses it, then plays a sound file.

// Play default sound
audio.Play();

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

// When the audio component has stopped playing, play otherClip
var otherClip : AudioClip;

function Update()
{
 if(!audio.isPlaying)
 {
  audio.clip = otherClip;
  audio.Play();
 }
}

you could modify it so that it plays and stops the sound when you hit that wall:

var Sound2 : AudioClip;
function OnTriggerEnter(hit : collider)
{
 if(hit.gameObject.tag == "PlayStop")
 {
  audio.pause;
  audio.clip = Sound2;
  audio.Play(Sound2);
 }
}

that last one might not work, but i know the top one works perfectly. and don't forget to tag your wall "PlayStop" !!!!

okay. to pause an already playing sound, just do

var Sound1 : AudioClip;
var Sound2 : AudioClip; 

function OnTriggerEnter(hit : Collider)
{
 if(hit.gameObject.tag == "PlayStop")
 {
  audio.Pause(Sound1);
  audio.Play(Sound2);
 }
}