Audio on and off for complete flash movie

programming flash
1

I need to turn my audio off with a simple button and back on with the same one, the audio from all the movies attached to the main movie should be off when I press this button


bgSound = new Sound(this);
itquit = false;
itgoes = true;
bgSound.attachSound("sound1");
bgSound.start(0.99);
Btn_Mute.onPress = function()
{
 if (bgSound.getVolume() != 0)
 {
  Btn_Mute.gotoAndPlay(2);
  oldVolume = bgSound.getVolume();
  bgSound.setVolume(0);
 }
 else
 {
  Btn_Mute.gotoAndPlay(1);
  bgSound.setVolume(oldVolume);
 }
};

this is what i have but its not working.
i have different .wav throughout my flash and my button is correct, is called Btn_Mute.

please help.

thank you.