rem: virtual QWidget* validate(QString&)      { return 0; }
add: QWidget* DayWeekRule::validate(QString& errorMessage) { for (int i = 0;  i < 7;  ++i) if (mDayBox[i]->isChecked()) return 0; errorMessage = i18n("No day selected"); return mDayBox[0]; }
context: 		virtual QWidget* validate(QString&)      { return 0; }