Function ROT13(strString) 'As String
'ROT13 substitutes each letter for one that is 13 characters 
'further in the alphabet. "A" becomes "N", "B" becomes "O", 
'and so on. This is a symetrical code (encoding and decoding
'by the same function)
Const DOUBLE_ALPHABET = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ"
Dim strROT13
Dim lngPos
Dim intChar
	For lngPos = 1 To Len(strString)
		intChar = Instr(DOUBLE_ALPHABET, Mid(strString, lngPos, 1))
		If intChar = 0 Then
			strROT13 = strROT13 & Mid(strString, lngPos, 1)
		Else
			strROT13 = strROT13 & Mid(DOUBLE_ALPHABET, intChar + 13, 1)
		End If
	Next
	ROT13 = strROT13
End Function