code: public void weeksChange(String week, Boolean value) {
  
          final WeekOfMonth changedWeek = WeekOfMonth.valueOf(week);
          boolean newValue = (null != value) && value.booleanValue();
          boolean currentValue = m_model.getWeeksOfMonth().contains(changedWeek);
          if (newValue != currentValue) {
              if (newValue) {
                  setPatternScheme(true, false);
                  m_model.addWeekOfMonth(changedWeek);
                  onValueChange();
              } else {
                  removeExceptionsOnChange(new Command() {
  
                      public void execute() {
  
                          m_model.removeWeekOfMonth(changedWeek);
                          onValueChange();
                      }
                  });
              }
          }
      }
docs: Handle a change in the weeks of month.
  @param week the changed weeks checkbox's internal value.
  @param value the new value of the changed checkbox.