script 2

drawZombiesCounter()
{
    level.zombiesCountDisplay = createServerFontString("Objective" , 1.7);
    level.zombiesCountDisplay setPoint("RIGHT", "CENTER", 315, "CENTER");

    thread updateZombiesCounter();
}

updateZombiesCounter()
{
    level endon("stopUpdatingZombiesCounter");

    while(true)
    {
        zombiesCount = get_current_zombie_count();
        level.zombiesCountDisplay setSafeText("Zombies: " + zombiesCount);

        waitForZombieCountChanged("stopUpdatingZombiesCounter");
    }
}

recreateZombiesCounter()
{
    level notify("stopUpdatingZombiesCounter");

    thread updateZombiesCounter();
}

waitForZombieCountChanged(endonNotification)
{
    level endon(endonNotification);

    oldZombiesCount = get_current_zombie_count();

    while(true)
    {
        newZombiesCount = get_current_zombie_count();

        if(oldZombiesCount != newZombiesCount)
        {
            return;
        }

        wait 0.05;
    }
}