import flash.utils.Timer;
import flash.events.TimerEvent;

timer2.visible = false;

var fl_TimerInstance:Timer = new Timer(1000,4);
fl_TimerInstance.addEventListener(TimerEvent.TIMER, fl_TimerHandler);
fl_TimerInstance.start();

var fl_SecondsElapsed:Number = 3;

function fl_TimerHandler(event:TimerEvent):void
{
    timer1.text = ("Seconds elapsed: " + fl_SecondsElapsed);
    fl_SecondsElapsed--;

    if(fl_SecondsElapsed <0)
    {
        timer2.visible = true;
    }
}