how to decrypt encrypted text

Public Function SimpleCrypt1( _
    ByVal encrypt As String) As String
       ' Encrypts/decrypts the passed string using
       ' a simple ASCII value-swapping algorithm
       Dim strTempChar As String, i As Integer
       For i = 1 To Len(Text)
           If Asc(Mid$(Text, i, 1)) < 128 Then
               strTempChar = _
         CType(Asc(Mid$(Text, i, 1)) + 128, String)
           ElseIf Asc(Mid$(Text, i, 1)) > 128 Then
               strTempChar = _
         CType(Asc(Mid$(Text, i, 1)) - 128, String)
           End If
           Mid$(Text, i, 1) = _
               Chr(CType(strTempChar, Integer))
       Next i
       Return Text
   End Function