code: public String convertIndexToString(int index)
      {
          String[][] rgstring = this.getPopupMap();
          if (index >= rgstring.length)
              index = 0;
          return rgstring[index][0];
      }
docs: Convert this index to a string.
  This method is usually overidden by popup fields.
  @param index The index to convert.
  @return The display string.