Noob query on Buttons

Noob query on Buttons

Dear all,
Here comes a very ”noob query” about Buttons.
My need is to have a button that can toggle a parameter on/off like “mute”/ "unmute” – and I’d like that to be a button – and upon selection it is to be replaced with an indentical (or similar) button including a red cross or so to indicate “Off” which appears in the same place on the stage. I know this should be trivial stuff – but not for me, I am a computational programmer (Fortran etc) at heart and know close to nothing about the graphic part of FLASH.

I do know that the graphics (skin buttons) should be placed in separate layers, and all my neat AS3 code in a separate layer.

So how can I do the above?

PLS advice,
jaxz