AS3 not working

play_pause.addEventListener(MouseEvent.CLICK, change_sound);

function change_sound (e:MouseEvent):void{
	if(muted){
		fl_NS.soundTransform = normalAudio;
		e.target.visible = true;
		trace(play_pause.visible);
		muted = false;
	}
	else{
		fl_NS.soundTransform = muteAudio;
		e.target.visible = false;
		trace(play_pause.visible);
		muted = true;
	}
}

var fl_NC:NetConnection = new NetConnection();
fl_NC.connect(null);    // starts a connection; null is used unless using Flash Media Server

var fl_NS:NetStream = new NetStream(fl_NC);
fl_NS.client = {};

var fl_Vid:Video = new Video();
fl_Vid.attachNetStream(fl_NS);
addChild(fl_Vid);

fl_NS.play("http://localhost.sites/foundbite/media/3003397718.m4a");
fl_NS.addEventListener(NetStatusEvent.NET_STATUS, onNetStatus);

function onNetStatus(event:NetStatusEvent):void
{
	var code:String=event.info.code;
	// trace(code);
	switch(code)
	{
		case "NetStream.Buffer.Empty":
			fl_NS.seek(0);
			break;
		case "NetStream.Seek.Notify":
			var seekPoint:Number = event.info.seekPoint;
			//trace("seeking to: ", seekPoint);
			break;
	}
}

var muteAudio:SoundTransform = new SoundTransform();
var normalAudio:SoundTransform = new SoundTransform();
var muted = false;
muteAudio.volume = 0;
normalAudio.volume = 1;