private String getIndexText(int index, int colour) {
      assert (colour == PL_WHITE || colour == PL_BLACK);
      assert (index >= 0 && index <= 15);

      String result = "";

      // Get the column
      result += col_text[index % 8];

      // Get the row
      if (colour == PL_WHITE) {
        result += (index <= 7) ? "2" : "1";
      }
      if (colour == PL_BLACK) {
        result += (index <= 7) ? "7" : "8";
      }
      return result;
    }