flex 4.6 倒计时组件

<?xml version="1.0" encoding="utf-8"?>
<s:Group xmlns:fx="http://ns.adobe.com/mxml/2009"
         xmlns:s="library://ns.adobe.com/flex/spark"
         xmlns:mx="library://ns.adobe.com/flex/mx"
         width="486" height="82" creationComplete="init()" fontWeight="bold">
    
    <fx:Script>
        <![CDATA[
            import flash.events.Event;
            import flash.events.TimerEvent;
            import flash.media.Sound;
            import flash.media.SoundChannel;
            import flash.utils.Timer;
            
            import mx.controls.Alert;
            import mx.events.CloseEvent;
            import mx.events.ColorPickerEvent;
            
            private  var timer:Timer;
            public  var h_num:int=0;
            public  var m_num:int=0;
            public var s_num:int=10;
            public var sumit:Function;
            private function init():void
            {
                this.timeComplete();
                timer = new Timer(1000, 0);
                timer.addEventListener(TimerEvent.TIMER, onTimer);
                timer.start();
            }
            
            private function onTimer(event:TimerEvent):void
            {
                s_num = s_num - 1;
                
                if ((s_num == -1) && (m_num > 0)) 
                {
                    m_num = m_num - 1;
                    s_num = 59;
                }
                if ((m_num == 0) && (h_num > 0))
                {
                    h_num = h_num -1;
                    m_num = 59;
                    s_num = 59;
                }
                if(s_num<30 && h_num==0 && m_num==0){
                    tip.text="距离考试结束还有"+s_num+"秒，请您尽快提交当前题的答案哦！";
                }
                if (s_num < 0)
                {
                    s_num = 0;
                    timer.stop();
                    
                    Alert.yesLabel = "确定";
                    Alert.show("考试结束时间到！", "提示", Alert.YES, this, function(event:CloseEvent):void{
                        var flag:int = event.detail;
                        if(flag == Alert.YES){
                            Alert.show("YES");
                          //sumit.call();
                        }
                    });
                }
        
                var hh:String;
                var mm:String;
                var ss:String;
                hh = (h_num < 10) ? "0" + h_num.toString() : h_num.toString();
                mm =  (m_num < 10) ? "0" + m_num.toString() : m_num.toString();
                ss = (s_num < 10) ? "0" + s_num.toString() : s_num.toString();
                time2_txt.text = time_txt.text = hh + "小时" + mm + "分" + ss+"秒"; 
            }
            
            private function timeComplete():void
            {
                var hh:String;
                var mm:String;
                var ss:String;
                hh = (h_num < 10) ? "0" + h_num.toString() : h_num.toString();
                mm =  (m_num < 10) ? "0" + m_num.toString() : m_num.toString();
                ss = (s_num < 10) ? "0" + s_num.toString() : s_num.toString();
                time2_txt.text = time_txt.text = hh + ":" + mm + ":" + ss; 
            }

        ]]>
    </fx:Script>
 <fx:Declarations>
    <mx:RadioButtonGroup id="colorSel" />
 </fx:Declarations>    
    <mx:Text id="time2_txt" x="211" y="5" width="273" height="45" color="#9CF5D7" fontSize="30"
             fontWeight="bold"/>
    <mx:Text id="time_txt" width="275" height="44" fontSize="30" color="#BE03FC" fontWeight="bold" x="208" y="3"/>
    <s:Label x="10" y="15" width="199" height="32" color="#FBE703" fontFamily="中易黑体" fontSize="22"
             fontWeight="bold" text="距离考试结束还有："/>
    <s:Label x="24" y="51" width="439" height="22" color="#FD0303" fontSize="16" id="tip"/>
</s:Group>