Using scenes and marking them as dirty in AS2

I am Not a regular AS developer but had learnt it in college.

Here is the problem
I have a movieclip with > 80 scenes.
Each scene has a backbutton, a nextbutton and a re-play button.
The user may use the re-play button to play the audio.
The audio must play the first time the scene is visited
On subsequent visits (via the back button or other links) the audio must not play automatically.
How to mark the scene as visited to avoid the audio playing on subsequent visits

Solution logic that I have is
*Use the movieclip.scenes array
create a 2 dimension array
store the scene name (from the scenes array) in index 0
and the state in index 1
use the currentscene property to check the value of the state from the 2 dimensional array
play the audio if the state is not dirty

**I need
**the code and where to put it
(I put all my actions on a separate layer called action, will that do?)

This is really urgent as at the moment it is a show stopper on an important project