FileMaker Pro Custom Functions

/* ROT13 (Caesar-Cipher by 13 chars) is a cipher commonly used in Usenet postings. The term cipher itself might be a bit misleading: The ROT13-algorithm is based on a rotation of all alphabetic characters by 13. Speaking in computer terms the ASCII-values of the letters are incremented or decremented by 13. In addition to ROT13, ROT5 is often used to encrypt digits, which means that every digit is rotated by 5. The beauty of the ROT13 is that you can use the same formula to decrypt. This encryption method is found often on Usenet, and you can use it to hide somethings from your kids (if they are under 8 years of age) ;-) */ Let([ numbers="0123456789"; characters="ABCDEFGHIJKLMNOPQRSTUVWXYZ"; firstChar=Left(text;1) ] ; If(Length(text) >0; Case( PatternCount(numbers; firstChar) >0; Middle(numbers&numbers;Position(numbers;firstChar;1;1)+5;1); PatternCount(characters; firstChar) >0; If( Exact(firstChar;Upper(firstChar)); Middle(characters&characters;Position(characters;firstChar;1;1)+13;1); Middle(Lower(characters&characters);Position(characters;firstChar;1;1)+13;1) ); // end if firstChar) //end Case & Rot13(Middle(Text;2;999999999999999)) ;"" ) // end if ) //end let
 Then copy & paste into FileMaker Advanced's Edit Custom Function window.