Switching/Swapping Out Movieclips

Hi guys,

I’m trying to make a mute button in my Flash banner that changes icons when pressed.
Here is the code I’m currently using:

music = new Sound();
music.attachSound("SoundFileName");
music.start(0, 1);
music.setVolume(0);
vol = 0;

step = 3;
fade = 0;

onEnterFrame = function() {
  if (fade == 1) {
    vol = vol-step;

  if (vol<0) {
    vol = 0;
  }
  music.setVolume(vol);
  } else {
   vol = vol+step;
  if (vol>100) {
   vol = 100;
   }
  music.setVolume(vol);
  }
}

And this is attached to the button:

on (release) {
        (_root.fade=!_root.fade) ? 0 : 1;
}

I searched for this problem online for hours, and I found this code:

muteButton.attachmovie("newButtonLinkage", "NewName", 1);

But where should I put this code? Or should I attach it to the button? What else do I need to do to get it to work? Do I need to change my original code attached to the mute button or in the frame that calls the sound? I’m a bit lost at this point.

Any help is greatly appreciated! Thanks!

-RC