Use code tags:
Using code tags properly page-2#post-3353071
Also… lower-case letter a is int 97, and they climb incrementally to z = 122. This means if you convert the char to an int and subtract 97, you’ll get a int from 0-25. The 26 indices of your array.
char letter = word.text[i];
if(!char.IsLetter(letter)) continue; //someone typed in a none letter, skip to the next letter in the loop
int index = (int)char.ToLower(letter) - 97; //ensure you tolower incase someone typed in upper-case