I know this can't be the right code to play on mp3 in flash movie

Question

I just feel that this is not the right code to playing sound if actionscript 3. I'm trying to play a mp3 sound only in flash can someone tell what is the right script to use. This is what I' m using.
stop();
play_btn.addEventListener(MouseEvent.CLICK, playSound);
goback_btn.addEventListener(MouseEvent.onRelease, goSound);
stop_btn.addEventListener(MouseEvent.CLICK, stopSound);
function playSound(e:MouseEvent):void {
    this.play();
function goSound(e:MouseEvent):void {
    this.gotoAndPlay("1");
function stopSound(e:MouseEvent):void {
    this.stop();
thanks

Answer 1

it's in my library
I figured out how to write code for mp3 to play
Now I can't write one to make it stop or gotoAndPlay.
This is my code to play
play_btn.addEventListener(MouseEvent.CLICK, playMusic);
function playMusic(e:MouseEvent):void {
    var myMusic:Sound = new Sound();
    var soundFile:URLRequest = new URLRequest("custodiansofkingdom.mp3");
    myMusic.load(soundFile);
    myMusic.play();
Can someone tell me how to write code to make it stop and gotoAndPlay
Thanks