Playing two audios at a time

Question

I made a speaker check. That is working fine. But if i duble click speakrOn button sound playing 2 times (two audios at a time).
How to solve my problem?
var mySound:Sound = new Sound();
var myChannel:SoundChannel = new SoundChannel();
mySound.load(new URLRequest("testAudio.mp3"));
speakrOn.addEventListener(MouseEvent.CLICK, onClickPlay);
speakrOff.addEventListener(MouseEvent.CLICK, onClickPlay);
function onClickPlay(e:MouseEvent):void
          speakrOn.visible = true;
          speakrOff.visible = false;
          myChannel = mySound.play();
          myChannel.addEventListener(Event.SOUND_COMPLETE, onAudioCompleteHandler);
function onAudioCompleteHandler(e:Event):void
          speakrOn.visible = false;
          speakrOff.visible = true;

Answer 1

var mySound:Sound = new Sound();
var myChannel:SoundChannel = new SoundChannel();
var isPlaying:Boolean = false;
mySound.load(new URLRequest("testAudio.mp3"));
speakrOn.addEventListener(MouseEvent.CLICK, onClickPlay);
speakrOff.addEventListener(MouseEvent.CLICK, onClickPlay);
function onClickPlay(e:MouseEvent):void
         speakrOn.visible = true;
         speakrOff.visible = false;
          if (!isPlaying)
               myChannel = mySound.play();
               myChannel.addEventListener(Event.SOUND_COMPLETE, onAudioCompleteHandler);
                isPlaying = true;
function onAudioCompleteHandler(e:Event):void
          isPlaying = false;
          speakrOn.visible = false;
          speakrOff.visible = true;