How create timer for game?

Question

I want to know how much time player spend in the game.
For this i want create a timer.
I thing it must be something like this:
player come to the game (time 0:00), player plaing for example 22 minutes, gameover game (player spend 22 minutes and 0 sec).
code:
import flash.utils.getTimer;
var gameStartTime:uint;
var gameTime:uint;
var gameTimeField:TextField;
function mainFunction():void
     gameTimeField = new TextField();
     addChild(gameTimeField);
     gameStartTime=getTimer();
     gameTime=0;
     addEventListener(Event.ENTER_FRAME,showTime);
function showTime(event:Event)
     gameTime=getTimer()-gameStartTime;
     gameTimeField.text="You plaing: "+clockTime(gameTime)+"min";
function clockTime(ms:int)
     var seconds:int=Math.floor(ms/1000);
     var minutes:int=Math.floor(seconds/60);
     seconds-=minutes*60;
     var timeString:String=minutes+":"+String(seconds+100).substr(1,2);
     return timeString;
mainFunction();
Is this correct way?
If you know how to make code smaller can you please share?
Maybe exist standart component or something else for this?
Thank you.

Answer 1

Thank you guys!
Just asking how to make timer correct:)
I thout maybe you know existing standart coder or standart component for it?
For example i use the same timer for 5 games.. and for every game i need create code..  Is it possible to make code just one time and create something like standart components in Flash IDE ? Or maybe adobe have place where everyone can create components and share whit other? Or its all not possible, and need create the same code again?
By the way why i dont see my secons here?:
var gameStartTime:uint;
var gameTime:uint;
function mainFunction():void
     gameStartTime=getTimer();
     gameTime=0;
     addEventListener(Event.ENTER_FRAME,showTime);
function showTime(event:Event)
     gameTime=getTimer()-gameStartTime;
     myText.text="Time: "+clockTime(gameTime);
function clockTime(ms:int)
     var seconds:int=Math.floor(ms/1000);
     var timeString:String=String(seconds+100).substr(1,2);
mainFunction();