if (f == null) return;
   protected void closeSession(Session targetSession) {      Gui5250Frame f = getParentView(targetSession);      int tabs = f.getSessionViewCount();      Sessions sessions = manager.getSessions();      Session session = null;      if (tabs > 1) {         if ((sessions.item(targetSession)) != null) {            f.removeSessionView(targetSession);            manager.closeSession(targetSession);            targetSession = null;         }      }      else {         closingDown(f);      }   }