switch (tab.State(kExkZw)) {
case HistZstEnum.Unknown:
	Program.Log("no value found for {0}", kExkZw);
	break;
case HistZstEnum.Aktiv:
	break;
default:
	Program.Log("state {1} for {0} not marked as active", kExkZw, tab.State(kExkZw));
	break;
}