Audio on/off

Hi GuysI'm trying to set up an audio button which operates like a mute button. So for example the user is presented with an initial introduction page where he is asked to turn the audio on or off for the module. This then filters through to every page and if the user wants to turn the audio back on they can just click the button again which will then filter through for the remainder of the module.I have tried playing about with variables but am struggling to apply actions to audio when they are invisible hence the on show becomes difficult and I also cant seem to get the thing to carry through the right button and audio command.Any help would be greatly appreciated