| File name: Encrypt.pql
| Creator:   David Merle
| Created:   10/16/2007
| Called by: Any program that wants to call it
| Reason:    Encrypts any string and returns the coded version. If used on an encrypted string, it returns the
|            unencrypted string.
| Output:    An encrypted or unencrypted string
subroutine UTIL.ENCRYPT (IN$)
         returning (CODED$)
         replace
         nodatabase
. integer * 2 ASCII                             | Store the ASCII value of a character
. ASCII = 0
. string * 300 IN$                              | Input string (to be coded)
. string * 300 CODED$                           | Coded string
. set CODED$ ('')
. for x = 1, len(IN$)                           | For the length of the input string
.   ASCII = ichar(sbst(IN$, x, 1))              | Convert each character into its ASCII value
.   ifthen (amod(x,4) = 0)                      | For every 4th character
.     ifthen (ASCII > 64 and ASCII < 91)        | For capital letters
.       ASCII = ASCII + 32                      | Change them to lower case
.     elseif (ASCII > 96  and ASCII < 123)      | For lower case
.       ASCII = ASCII - 32                      | Change them to upper case
.     endif
.   endif
.   ifthen ((ASCII > 64 and ASCII < 78) or (ASCII > 96 and ASCII < 110))        | Switch letters around
.     CODED$ = CODED$ + char(ASCII + 13)                                        | in a uniform way
.   elseif ((ASCII > 77 and ASCII < 91) or (ASCII > 109 and ASCII < 123))       | so that the same process
.     CODED$ = CODED$ + char(ASCII - 13)                                        | will revert them to their
.   elseif (ASCII > 31 and ASCII < 49)                                          | original values.
.     CODED$ = CODED$ + char(ASCII + 17)
.   elseif (ASCII > 48 and ASCII < 65)
.     CODED$ = CODED$ + char(ASCII - 17)
.   endif
. end for
end subroutine