Mute soundchannel on leavingframe

1

Greetings, here is my query:

my soundchannel plays when i enter frame 7, I would like it to mute when i exit frame 7.

easy.

this is my wrong code:

var soundFactory7:Sound = new Sound;
        
		
		var channel7:SoundChannel = new SoundChannel();
       
	   var positionTimer7:Timer;
	   
	   var transform7 = new SoundTransform();

channel7.soundTransform = transform7;

  soundFactory7 = new Sound(new URLRequest("tcp_d1_05_5_dashes_irdial.mp3"));

channel7 = soundFactory7.play();
			
			
			channel7.soundTransform = transform7;
if (currentFrame == 7) {


transform7.volume = 1;
}


else {
	
	transform7.volume = 0;
}
            channel7.addEventListener(Event.SOUND_COMPLETE, soundCompleteHandler7);

            positionTimer7 = new Timer(50);
            //positionTimer.addEventListener(TimerEvent.TIMER, positionTimerHandler);
            positionTimer7.start();
        
         function soundCompleteHandler7(event:Event):void {
            trace("soundCompleteHandler7: " + event);
            positionTimer7.stop();
			channel7 = soundFactory7.play();
			channel7.addEventListener(Event.SOUND_COMPLETE, soundCompleteHandler7);
			
		 }

thanks for your time