StopWatch AS3

import flash.text.TextField;
import flash.display.MovieClip;
import flash.events.MouseEvent;
import flash.utils.Timer;
import flash.events.TimerEvent;


var tTime:TextField;
var tLap:TextField;
var bStart:MovieClip;
var bStop:MovieClip;
var bLap:MovieClip
var timer:Timer;
var mic:int;
var sec:int;
var min:int;

function init():void
{
    // -----------------------------
    tTime = new TextField();
    tLap = new TextField();
    tTime.width = 200;
    tTime.x = 100;
    tLap.x = 300;
    tTime.y = tLap.y = 50;
    tTime.text = "00:00:00";
    tLap.text = "Lap Column";
    addChild(tTime);
    addChild(tLap);
    // -----------------------------
    bStart = new btn_start();
    bStop = new btn_stop();
    bLap = new btn_lap();
    bStart.x = 100;
    bStop.x = 200;
    bLap.x = 300;
    bStart.name = "START";
    bStop.name = "STOP";
    bLap.name = "LAP";
    bStart.y = bStop.y = bLap.y = 300;
    addChild(bStart);
    addChild(bStop);
    addChild(bLap);
    bStart.addEventListener(MouseEvent.CLICK,handleClick,false,0,true);
    bStop.addEventListener(MouseEvent.CLICK,handleClick,false,0,true);
    bLap.addEventListener(MouseEvent.CLICK,handleClick,false,0,true);
    // -----------------------------
    timer = new Timer(50);
    timer.addEventListener(TimerEvent.TIMER,updateWatch,false,0,true);
    mic = 0;
    sec = 0;
    min = 0;
}

function handleClick(e:MouseEvent):void
{
    switch(e.target.name)
    {
        case "START":
            timer.start();
        break;
        case "STOP":
            mic = sec = min = 0;
            timer.stop();
            timer.reset();
        break;
        case "LAP":
            tLap.appendText("\n" + tTime.text);
            tTime.text = "00:00:00";
            mic = sec = min = 0;
        break;
    }
}

function updateWatch(e:TimerEvent):void
{
    mic += 5;
    if(mic >= 60){
        mic = 0;
        sec++;
        if(sec >= 60){
            sec = 0;
            min++;
            if(min >= 60)min = 0;
        }
    }
    var strMic:String = String(mic);
    if(strMic.length < 2)strMic = "0" + strMic;
    var strSec:String = String(sec);
    if(strSec.length < 2)strSec = "0" + strSec;
    var strMin:String = String(min);
    if(strMin.length < 2)strMin = "0" + strMin;

    tTime.text = strMin + ":" + strSec + ":" + strMic;
}

init();