$code_letter_array = array();
$code_letter_array[] = '0';
$code_letter_array[] = 'A';
$code_letter_array[] = 'B';
$code_letter_array[] = 'C';
$code_letter_array[] = 'D';
$code_letter_array[] = 'E';
$code_letter_array[] = 'F';
$code_letter_array[] = 'G';
$code_letter_array[] = 'H';
$code_letter_array[] = 'I';
$code_letter_array[] = 'J';
$code_letter_array[] = 'K';
$code_letter_array[] = 'L';
$code_letter_array[] = 'M';
$code_letter_array[] = 'N';
$code_letter_array[] = 'O';
$code_letter_array[] = 'P';
$code_letter_array[] = 'Q';
$code_letter_array[] = 'R';
$code_letter_array[] = 'S';
$code_letter_array[] = 'T';
$code_letter_array[] = 'U';
$code_letter_array[] = 'V';
$code_letter_array[] = 'W';
$code_letter_array[] = 'X';
$code_letter_array[] = 'Y';
$code_letter_array[] = 'Z';