No sound from Flash CS5?

Question

I have 1.mp3 beside my .fla file and when I tried to run a movie test, it doesn't play any sounds. Only the stage has a glitch was it keep loop frame 1 and 2. What happen?

var mySoundReq:URLRequest = new URLRequest("1.mp3");
var mySound:Sound = new Sound();
mySound.load(mySoundReq);
mySound.addEventListener(Event.COMPLETE, playSong);

function playSong(event:Event):void {
mySound.play();
}

My test Movie with button on stage: http://img156.imageshack.us/img156/9950/cs5c.jpg