var nowfullscreen = window_get_fullscreen();
if (nowfullscreen != isfullscreen)
{
    ini_open("true_config.ini");
    ini_write_real("SCREEN", "FULLSCREEN", nowfullscreen);
    ini_close();
    if (!nowfullscreen)
    {
        window_set_size(640 * window_size_multiplier, 480 * window_size_multiplier);
        alarm[0] = 1;
    }
}
isfullscreen = nowfullscreen;