title: unity 4.6 UI how to set a slider main volume for all sound?
body: <p>I wish someone can tell me how to set audiolistener main volume for a slider with the new UI system.
  I mean i know I can do with audio source but how can I do for all audio file togheter that has already a slider volume their own?
  When I put the main camera in the On Value change field and set audio Listerner-->volume it says: Missing AudioListener.set_volume</p>
  
  <p>While I did this with old gui system via script now I'm a bit confused how it works.</p>