What I mising? The number of columns in pdfptable constructor must be greater than zero

The number of columns in PdfPTable constructor must be greater than zero

<pre>

private static DataTable dt = new DataTable();
/////////////////////////////////////////////////////////


private static void slanjeizvestaja()
        {
            String cs = "Data Source=.\\SQLEXPRESS;Initial Catalog=bss_prijava_radnika;Integrated Security=True";
            using (SqlConnection openCon = new SqlConnection(cs))

            {

                string pronadji = "SELECT p.brojprijavnice2 AS Redni_broj, p.radnik AS Radnik, p.vrijemeprijave AS Vrijeme_Prijave, p.vrijemeodjave AS Vrijeme_odjave"
                                 + " FROM dbo.prijava_radnika p WHERE p.status = 'odjavljen'";



                openCon.Open();
                using (SqlDataAdapter querySaveStaff = new SqlDataAdapter(pronadji, cs))

                {
                    DataTable dt = new DataTable();
                    querySaveStaff.Fill(dt);
                }
                openCon.Close();
            }
        }

        private static void sendEmail()
        {


            PdfPTable pdfTable = new PdfPTable(dt.Columns.Count);
            pdfTable.DefaultCell.Padding = 3;
            pdfTable.WidthPercentage = 100;
            pdfTable.HorizontalAlignment = Element.ALIGN_LEFT;
            pdfTable.DefaultCell.BorderWidth = 1;
            BaseFont bfCalibri = BaseFont.CreateFont("c:\\windows\\fonts\\calibri.ttf", BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
            iTextSharp.text.Font calibri = new iTextSharp.text.Font(bfCalibri, 12);