docs: public void init(BaseField field, ScreenComponent screenField, BaseField fldTarget)
      {
          super.init(field);
          m_screenField = screenField;
          m_fldTarget = fldTarget;
  
          m_bScreenMove = true;   // Only respond to user change
          m_bInitMove = false;
          m_bReadMove = false;
          if (screenField == null)
              this.lookupSField();
      }