public String getChess_column_position(int position){
        switch (position) {
            case 0:  return "a";
            case 1:  return "b";
            case 2:  return "c";
            case 3:  return "d";
            case 4:  return "e";
            case 5:  return "f";
            case 6:  return "g";
            case 7:  return "h";
        }
		return null;
	}