WIN_INUSE
if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) {
msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
if (msc_win_set_lockout(msc->cur_win, WIN_READY, WIN_INUSE))
msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);