rebol [ title: "rot13" author: "vpavlu" date: 9-Dec-2002/13:12 home: http://plain.at/vpavlu ] filename: to-file ask "file to scramble? " string: read filename foreach char string [ either ((char >= #"A") and (char <= #"Z")) [ char: char + 13 if char > #"Z" [ char: char - 26] ][ if ((char >= #"a") and (char <= #"z")) [ char: char + 13 if char > #"z" [ char: char - 26 ] ] ] prin char ]