code: public void setControlValue(Object objValue)
      {
          if (objValue instanceof Boolean)
          {
              if (((Boolean)objValue).booleanValue())
                  m_iCurrentState = ON;
              else
                  m_iCurrentState = OFF;
          }
          else
              m_iCurrentState = NULL;
          this.updateImage();
      }
docs: Set the value.
  @param objValue The raw data (a Boolean).