Code:
var music:Sound = new Sound(this);
music.attachSound("mySound");
music.start(0, 5);
_root.onEnterFrame = function() {
var soundlevel:Number = music.getVolume();
soundlevel -= 5;
music.setVolume(soundlevel);
if (soundlevel<=0) {
delete this.onEnterFrame;
}
};
put code in appropriate place