Displaying elapsed time

[Chiapa]

Hi again,

in my game (where alienships fly across the screen and I shoot them with a crosshair) I need to display the time elapsed since the start of the game. Here is the code of the Main class, the spaceship class isn't needed. I'm trying this but it only displays zero (0) and never changes.

This is the Main class:

package
{
    import flash.display.MovieClip;
    import flash.events.MouseEvent;
    import flash.ui.Mouse;
    import flash.events.TimerEvent;
    import flash.utils.Timer;
    import flash.utils.getTimer;
    import flash.events.Event;
    import flash.media.Sound;
    import flash.net.*;
    import flash.media.SoundChannel;

    public class Main extends MovieClip
    {
        
        var mycounter: Counter = new Counter();
        var initial_time;
        var current_time;
        var game_time;  
        
        var total:int = 200;
        var naves = new Array;
        var tempo:Timer;
        var tempo2:Timer;

        public var pontos:int = 0;
        
        var musica_fundo:Sound = new Sound();
        var tiro:Sound = new Sound();

        function Main():void
        {
            play_btn.addEventListener(MouseEvent.CLICK, jogar);
            
            function jogar(evt:MouseEvent):void
            {    
                if (currentFrame == 1)
                {
                    gotoAndStop(totalFrames);
                }
                else
                
                Mouse.hide();
                stage.addEventListener(MouseEvent.MOUSE_MOVE,mexe_mira);
                stage.addEventListener(MouseEvent.CLICK,som);

                init_naves();
                
                initCounter();
                
                tempo = new Timer(700,total);
                tempo.addEventListener(TimerEvent.TIMER,voa);
                tempo.start();

                tempo2 = new Timer(900,total);
                tempo2.addEventListener(TimerEvent.TIMER,voa2);
                tempo2.start();

                game_time.addEventListener(Event.ENTER_FRAME,contador);                


                tiro.load(new URLRequest("SFX/tiro4mp.mp3"));
            }
        }

        private function initCounter() {
            
            mycounter.x = stage.width - 30;
            mycounter.y = 40;
            addChild(mycounter);
            
            start_time= getTimer();
            game_time= 0;
            mycounter.text = start_time.toString();
            mycounter.mouseEnabled = false;
        }

        function som(event:MouseEvent)
        {
            tiro.play(0);
        }

        function contador(event:TimerEvent)
        {
            game_time= current_time - start_time;
            //mycounter.embedFonts = false;
            mycounter.text = game_time.toString();
        }

        private function voa(e:TimerEvent):void // função que põe as naves a "voar"
        {
            var nave = naves.pop();
            nave.voa();
        }

        private function voa2(e:TimerEvent):void
        {
            var nave = naves.pop();
            nave.voa2();
        }


        private function init_naves():void // função criadora das naves
        {
            var nave1;
            var nave2;

            for (var i = 0; i < total; i++) // criação de naves com x definido e y aleatório
            {
                nave1 = new Nave  ;
                nave1.x = -30;
                nave1.y = Math.floor(Math.random() * this.stage.stageHeight);

                nave1.addEventListener("clicked", onNaveClicked);
                this.addChild(nave1); // criação de nave
                naves.push(nave1);
            }
            
            
//            musica_menu.load( new URLRequest("Musica/MI.mp3"));
//            sndChannel.stop();
            musica_fundo.load(new URLRequest("Musica/Carmina.mp3")); // load da música de jogo
            musica_fundo.play(); // iniciação da reprodução da música
        }
        
        private function onNaveClicked(event:Event):void
        {
            this.pontos++;
            trace(this.pontos);
            pontos_txt.embedFonts = false;
            pontos_txt.text = String(pontos);
        }

        private function mexe_mira(event:MouseEvent) // função que define a posição da mira, seguindo o rato
        {
            Mouse.hide();
            mira.x = mouseX;
            mira.y = mouseY;
        }
    }
} 

Can anyone help? What am I doing wrong?

Thanks, Chiapa