Sound fading

I’ve asked in countless places, and I always get an answer I either don’t understand, or an answer that is COMPLETELY NOT WHAT I WANT.

Here’s the question, and I’m going to give an example (actually, a real flash that I’m working on).

This thing is a flash ID for a website I submit often too. It has a loop of a song that is quite cool, but anyway.
In the ID, I want people to be able to click an on and off button, the on button FADES the music on, and the off button FADES the music off. I want the music to fade, giving it a more polished look. Once again, I WANT THE MUSIC TO FADE. I know this is possible.
I want a script, as in an actionscript as to how to make this stuff fade on and off (and please, a script to make the music fade to a lower level of volume too).

So, here or the presquites of the script I either want or want help making.

  1. Music must FADE.

  2. Must be an ACTIONSCRIPT.

3.Do NOT give me the advice saying “If you go to the timeline, click on the song, then go to “edit”, you can change it there.” You can only do that a limited amount of times, and you can’t do it at any point you want.

  1. Please include COMMENTS all around the script so that I can tell what what does and what happens when what does what… right…

  2. Did I mention FADING.

  3. Please making the script applicable to different songs.

  4. Please elaborate on the script so I know exactly what to do.

  5. Please make it also possible with the script to FADE to lower levels of volume, and not just 0, but still FADE.

  6. If you help me, I cannot give you anything, I am sorry, except my undying thanks and gratitude.