###
# simple_code.py
#
# author: Kristina Striegnitz
#
# version: 1/21/2010
#
###

## Simple function to encode a letter. The function
## takes a letter as a parameter and returns another
## letter. For example, given "a", it return "b", given
## "b" it returns "c", etc.
def encode(letter):

    lower_letter = letter.lower()

    if lower_letter == "a":
        return "b"
    elif lower_letter == "b":
        return "c"
    elif lower_letter == "c":
        return "d"
    elif lower_letter == "d":
        return "e"
    elif lower_letter == "e":
        return "f"
    elif lower_letter == "f":
        return "g"
    elif lower_letter == "g":
        return "h"
    elif lower_letter == "h":
        return "i"
    elif lower_letter == "i":
        return "j"
    elif lower_letter == "j":
        return "k"
    elif lower_letter == "k":
        return "l"
    elif lower_letter == "l":
        return "m"
    elif lower_letter == "m":
        return "n"
    elif lower_letter == "n":
        return "o"
    elif lower_letter == "o":
        return "p"
    elif lower_letter == "p":
        return "q"
    elif lower_letter == "q":
        return "r"
    elif lower_letter == "r":
        return "s"
    elif lower_letter == "s":
        return "t"
    elif lower_letter == "t":
        return "u"
    elif lower_letter == "u":
        return "v"
    elif lower_letter == "v":
        return "w"
    elif lower_letter == "w":
        return "x"
    elif lower_letter == "x":
        return "y"
    elif lower_letter == "y":
        return "z"
    elif lower_letter == "z":
        return "a"
    else:
        return "?"