Automatic number with date format

[khabib28]

I have code to make autonumber with date format....

Call koneksi()
        cmd = New OleDbCommand("select * from penjualan order by no_faktur desc", conn)
        dr = cmd.ExecuteReader
        dr.Read()
        If Not dr.HasRows Then
            penfaktur.Text = "" + Format(Now, "ddMMyyyy") + "NF" + "0001"
        Else
            penfaktur.Text = Val(Microsoft.VisualBasic.Mid(dr.Item("no_faktur").ToString, 11, 4)) + 1
            If Len(penfaktur.Text) = 1 Then
                penfaktur.Text = "" + Format(Now, "ddMMyyyy") + "NF000" & penfaktur.Text & ""
            ElseIf Len(penfaktur.Text) = 2 Then
                penfaktur.Text = "" + Format(Now, "ddMMyyyy") + "NF00" & penfaktur.Text & ""
            ElseIf Len(penfaktur.Text) = 3 Then
                penfaktur.Text = "" + Format(Now, "ddMMyyyy") + "NF0" & penfaktur.Text & ""
            ElseIf Len(penfaktur.Text) = 4 Then
                penfaktur.Text = "" + Format(Now, "ddMMyyyy") + "NF" & penfaktur.Text & ""
            End If
        End If

I want every date change the number back to "0001" ..
help me..