Sound not playing with externally loaded swf

Hi, I have an swf sound file with a toggle button that i load into my main movie. The button shows but I get no sound.

this is how I have attached it:
_root.createEmptyMovieClip(“sound”, 200);
sound._x=745;
sound._y=41;
loadMovie(“sound.swf”,“sound”);

the script for my sound.swf is:
First frame of mc:
my_sound = new Sound();
my_sound.attachSound(“mix1”);
my_sound.start(0,1000);
gotoAndStop(“stop”);

second frame on button:
on (release) {
this.my_sound.start(0,1000);
this.gotoAndStop(“stop”);
}

thirdframe on button:
on (release) {
this.my_sound.stop();
this.gotoAndStop(“play”);
}

any help much appreciated.