Como criar um Timer que exibe a hora atualizada em um componente Label

<?xml version="1.0" encoding="iso-8859-1"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
  layout="absolute" applicationComplete="iniciarTimer()">

  <mx:Script>
    <![CDATA[
     import flash.utils.Timer;
     import flash.events.TimerEvent;
     
     private var timer:Timer;
     [Bindable]
     private var horaAtual:String;

     private function iniciarTimer():void{
       // inicia o timer
       timer = new Timer(1000);
       timer.addEventListener("timer", atualizarHoras);
       timer.start();
     }     

     private function atualizarHoras(event:TimerEvent):void{
       // atualiza as horas no label
       horaAtual = format.format(new Date()).toString();      
     }
    ]]>
  </mx:Script>

  <mx:Label id="horasLabel" fontSize="30" 
    text="{horaAtual}" />
  <mx:DateFormatter formatString="KK:NN:SS" id="format"/>

</mx:Application>