integer     COUNTDOWN;

default
{
    touch_start(integer total_number) {
    COUNTDOWN = 15;
        llSetTimerEvent(1);
    }
    timer() {
        if (COUNTDOWN) {
            COUNTDOWN--;
            llSetText("Countdown! Time left: "+(string)COUNTDOWN,<1,1,1>,1);
        }
        else {
            llSetTimerEvent(0);
            llSetText("BOom!",<1,0,0>,1);
        }
    }
}