docs: public int getDefaultDisplayFieldSeq()
      {
          String iKeyOrder = this.getDefaultScreenKeyArea();
          if (iKeyOrder == null)
          {
              for (int i = 0; i < this.getFieldCount(); i++)
              {
              	if (this.getField(i).isHidden())
              		continue;
                  if (this.getField(i) instanceof StringField)
                      return i;
              }
              return DBConstants.MAIN_FIELD + 1;
          }
          for (int i = 0; i < this.getFieldCount(); i++)
          {
              if (this.getField(i) == this.getKeyArea(iKeyOrder).getField(DBConstants.FILE_KEY_AREA))
                  return i;
          }
          return DBConstants.MAIN_FIELD + 1;
      }