code: public void addComponent(Object sField)
      {
          if (m_vScreenField == null)
              m_vScreenField = new Vector<Object>();
          m_vScreenField.addElement(sField);        // Notify this screen field if I change
      }
docs: This screen component is displaying this field.
  @param Object sField The screen component.. either a awt.Component or a ScreenField.