Flex NumericStepper在10以下的数字前加0？

package
{
    import flash.events.Event;

    import mx.controls.NumericStepper;
    import mx.core.mx_internal;
    import mx.events.FlexEvent;

    use namespace mx_internal;
    /**
     * Added support to format time values.
     */ 
    public class TimePickerNumericStepper extends NumericStepper
    {
        public function TimePickerNumericStepper()
        {
        }

        /**
         *  @private
         */
        override protected function createChildren():void
        {
            super.createChildren();
            onValueCommit(null)
            inputField.addEventListener(FlexEvent.VALUE_COMMIT,onValueCommit);
        }

        protected function onValueCommit(event:Event):void
        {
            if(value<10 && inputField.text.length==1){
                inputField.text = \"0\" + inputField.text;
            }   
        }


    }
}

<mx:NumericStepper id=\"stpprHours\" minimum=\"1\" maximum=\"24\" stepSize=\"1\" creationComplete=\"formatStepper(stpprHours)\" change=\"stpprHours_changeHandler(event)\" value=\"1\"/>

<mx:NumericStepper id=\"stpprMinutes\" minimum=\"0\" maximum=\"59\" stepSize=\"1\" creationComplete=\"formatStepper(stpprMinutes)\" change=\"stpprMinutes_changeHandler(event)\" value=\"0\"/>

<mx:Script>
 <CDATA[[
        protected function stpprHours_changeHandler(event:NumericStepperEvent):void {
            formatStepper(stpprHours);              
        }

        protected function stpprMinutes_changeHandler(event:NumericStepperEvent):void {
            formatStepper(stpprMinute);                             
        }

        protected function formatStepper(stepper : NumericStepper) : void {
            if(stepper.value<10) stepper.mx_internal::inputField.text = \"0\" + stepper.value;

    }
 ]]>
</mx:Script>

private function init( event:FlexEvent ):void{
        scheduleHour.addEventListener(Event.CHANGE,onStepperChange);
        scheduleMinute.addEventListener(Event.CHANGE,onStepperChange);
        scheduleHour.dispatchEvent(new Event(Event.CHANGE));
        scheduleMinute.dispatchEvent(new Event(Event.CHANGE));
}

        public function onStepperChange (ev:Event) : void {
            var stepper:NumericStepper  = ev.currentTarget as NumericStepper;
            var num:String = stepper.value > 10 ? \"\" + stepper.value : \"0\" + stepper.value;
            stepper.mx_internal::inputField.text = num;
        }