Function GetSONumber() As String
        Return GetSequenceNumber("S")
    End Function

    Function GetSequenceNumber(ByVal PrefixChar As String) As String

        PrefixChar = Left(PrefixChar + "X", 1)  ' in case blank

        Dim Mins As Integer
        Mins = DateDiff(DateInterval.Minute, CDate("2008-01-01"), GetServerTime)
        Return SplitIntoThrees(PrefixChar + ConvertBase30(Mins) + RandLetts(6))

    End Function

    Function RandLetts(ByVal Chars As Integer) As String

        ' letters that can easily be distinguished visually and audibally
        ' need to build routine to convert S to F for example and block others
        Dim V As String = "23456789ABCDEFGHJKLMNPRTUVWXYZ"
        Dim O As String = ""
        For I As Integer = 1 To Chars
            O = O + Mid(V, RollDice(Len(V)), 1)
        Next

        Return O
    End Function

    Function GetServerTime() As Date

        ' taken from http://www.codeproject.com/KB/vb/NetRemoteTOD.aspx
        ' removed daylight saving part as we want UTC

        ' see http://support.microsoft.com/kb/249716 for full usage info

        ' reverts to local PC time if can't connect

        Try
            Dim iRet As Integer
            Dim ptodi As IntPtr
            Dim todi As TIME_OF_DAY_INFO
            Dim dDate As Date
            Dim strServerName As String = "servername.local" & vbNullChar
            iRet = NetRemoteTOD(strServerName, ptodi)
            If iRet = 0 Then
                todi = CType(Marshal.PtrToStructure(ptodi, GetType(TIME_OF_DAY_INFO)),  _
                  TIME_OF_DAY_INFO)
                NetApiBufferFree(ptodi)
                dDate = DateSerial(todi.tod_year, todi.tod_month, todi.tod_day) + " " + _
                TimeSerial(todi.tod_hours, todi.tod_mins, todi.tod_secs)
                GetServerTime = dDate
            Else
                GetServerTime = Now.ToUniversalTime
            End If
        Catch
            GetServerTime = Now.ToUniversalTime
        End Try

    End Function

    Function SplitIntoThrees(ByVal CharsIn As String) As String

        Dim i As Integer
        Dim O As String = ""
        For i = 1 To Len(CharsIn)
            If (i - 1) Mod 3 = 0 And i <> 1 Then O = O + "-"
            O = O + Mid(CharsIn, i, 1)
        Next i
        SplitIntoThrees = O

    End Function

    Function RollDice(ByVal NumSides As Integer) As Integer
        ' Create a byte array to hold the random value.
        Dim randomNumber(0) As Byte

        ' Create a new instance of the RNGCryptoServiceProvider. 
        Dim Gen As New RNGCryptoServiceProvider()

        ' Fill the array with a random value.
        Gen.GetBytes(randomNumber)

        ' Convert the byte to an integer value to make the modulus operation easier.
        Dim rand As Integer = Convert.ToInt32(randomNumber(0))

        ' Return the random number mod the number
        ' of sides.  The possible values are zero-
        ' based, so we add one.
        Return rand Mod NumSides + 1

    End Function