Play pause button question

1

im making a play pause button and i have hit a wall.


var snd:Sound = new Sound(new URLRequest("combination.mp3"));

btn_mc.addEventListener(MouseEvent.CLICK, playSound);
btn_mc.buttonMode =true;
function playSound(event:MouseEvent):void
{
 snd.play();
btn_mc.removeEventListener(MouseEvent.CLICK, playSound);
btn_mc.addEventListener(MouseEvent.CLICK, stopSound);
}
function stopSound(event:MouseEvent):void
{
 snd.stop(); 
btn_mc.addEventListener(MouseEvent.CLICK, playSound);

}

any ideas where im going wrong?