if (obj_time.left)
{
    dongusvol -= 0.02;
    caster_set_volume(dangus, dongusvol);
    caster_set_volume(dongus, dongusvol - 1);
    caster_set_volume(dungus, dongusvol - 2);
}
if (obj_time.right)
{
    dongusvol += 0.02;
    caster_set_volume(dangus, dongusvol);
    caster_set_volume(dongus, dongusvol - 1);
    caster_set_volume(dungus, dongusvol - 2);
}