VB encryption and Decryption 问题

ycyc123

Dim result As String = ""
        password = TextBox1.Text
        For i = 1 To Len(Password)
            result = result & Chr(Asc(Mid(password, i, 1)) + 128)
        Next

        Label1.Text = result
我encryption密码了...
怎样decryption回？？？
result = result & Chr(Asc(Mid(password, i, 1)) - 128)

有error  = =