I have this code to generate a password with letters and digits:

        ' Generate a password
        ' expN1 Length of the password
        Public Function GeneratePwd(ByVal tnLength As Integer) As String
            Dim lcPassword As String = ""
            Dim lnCounter As Integer = 0
            Dim lnRandom As Integer = 0

            For lnCounter = 1 To tnLength
                If lnCounter = 1 Or Int(Rnd() * 100) Mod 2 = 0 Then
                    lnRandom = Int(Rnd() * 25) + 97
                Else
                    lnRandom = Int(Rnd() * 9) + 48
                End If
                lcPassword = lcPassword + Chr(lnRandom)
            Next

            Return lcPassword
        End Function

This code has been converted from VFP. However, this does not work very well in .NET. It practically always generates the same password. Anyone would have something better to recommend?