Round 2 of controlling sound

1

I now changed my movie up to where a “empty movie clip” is created that plays songs on maintime of movie. However, I still want to have a tab where it says “sound controls” be automated so that when users roll over it, it slides in and shows controls for sounds instead of them always being present. This roll over effect is the simple AS:


soundtab.onRollOver = over;
soundtab.onRollOut = out;
function over() {
 this.gotoAndPlay(2);
}
function out() {
 this.gotoAndPlay(15);
}

Now within this soundtab_mc I have 4 buttons; btn_play, btn_stop, btn_prev, btn_next that slide in as well.

Now the action script in maintime line of movie to create “empty movie clip” and to control it is as follows.


creation of XML and reading it ect.....
.............................................
  createEmptyMovieClip("sound_mc", 1);
  sound_mc.sound_obj = new Sound();
 _global.song_nr = random(songfile.length);
  sound_mc.songStarter(songfile[song_nr], songname[song_nr]);
};
MovieClip.prototype.songStarter = function(file, name) {
 this.sound_obj.loadSound(file, true);
 this.onEnterFrame = function() {
  if (this.sound_obj.position>0) {
   delete this.onEnterFrame;
   display_txt.text = name;
  } else {
   display_txt.text = "loading...";
  }
 };
 this.sound_obj.onSoundComplete = function() {
  (song_nr == songfiles.length-1) ? _global.song_nr=0 : _global.song_nr++;
   sound_mc.songStarter(songfiles[song_nr], songname[song_nr]);
 };
};
soundtab.btn_play.onRelease = function() {
     sound_mc.songStarter(songfile[song_nr], songname[song_nr]);
};
soundtab.btn_stop.onRelease = function() {
     sound_mc.sound_obj.stop();
};
soundtab.btn_next.onRelease = function() {
 (song_nr == songfile.length-1) ? _global.song_nr=0 : _global.song_nr++;
     sound_mc.songStarter(songfile[song_nr], songname[song_nr]);
};
soundtab.btn_prev.onRelease = function() {
 (song_nr == 0) ? _global.song_nr=songfile.length-1 : _global.song_nr--;
     sound_mc.songStarter(songfile[song_nr], songname[song_nr]);
};
playlist.load("playlist.xml");
stop();

The songs play and text of song is displayed in dynamic field however I get no response from my buttons. Does anyone have any ideas as to why my buttons are not working properly? Thanks in advance any help is appreciated.

MT