Membuat Nomor Otomatis di VB.Net 2008

Kodingnya Sbb :

Sub NomorOtomatis()
        cmd = New OdbcCommand("Select * from barang where kd_barang in (select max(kd_barang) from barang) order by kd_barang desc", conn)
        Dim urutan As String
        Dim hitung As Long
        rd = cmd.ExecuteReader
        rd.Read()
        If Not rd.HasRows Then
            urutan = "B" + "000" + "001"
        Else
            hitung = Microsoft.VisualBasic.Right(rd.GetString(0), 3) + 1
            urutan = "B" + "000" + Microsoft.VisualBasic.Right("000" & hitung, 3)
        End If
        kodeBarang.Text = urutan
    End Sub