CFStringRef local fn Encrypt( s as CFStringRef, key as int )
  CFMutableStringRef s1 = fn MutableStringWithString(s)
  for int i = 0 to len(s1) - 1
    unichar c = ucc(s1,i)
    select
      case ( c >= _"A" && c <= _"Z")
        c += key : if ( c > _"Z" ) then c -= 26
      case ( c >= _"a" && c <= _"z" )
        c += key : if ( c > _"z" ) then c -= 26
    end select
    mid(s1,i,1) = ucs(c)
  next
end fn = s1

CFStringRef local fn Decrypt( s as CFStringRef, key as int )
  CFMutableStringRef s1 = fn MutableStringWithString(s)
  for int i = 0 to len(s1) - 1
    unichar c = ucc(s1,i)
    select
      case ( c >= _"A" && c <= _"Z")
        c -= key : if ( c < _"A" ) then c += 26
      case ( c >= _"a" && c <= _"z" )
        c -= key : if ( c < _"a" ) then c += 26
    end select
    mid(s1,i,1) = ucs(c)
  next
end fn = s1

void local fn DoIt
  CFStringRef s = @"The sun's not yellow, it's chicken"
  print s

  s = fn Encrypt( s, 6 )
  print s

  s = fn Decrypt( s, 6 )
  print s
end fn

fn DoIt

HandleEvents