OleDbConnection con;

        private void dataGridView1_RowPostPaint_1(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            this.dataGridView1.Rows[e.RowIndex].Cells["column1"].Value = (e.RowIndex + 1).ToString();
        }

        private void btn_Browse_Click(object sender, EventArgs e)
        {
            //load file
            try
            {
                OpenFileDialog openfile1 = new OpenFileDialog();
                openfile1.Filter = "Excel Files|*.xls;*.xlsx";
                if (openfile1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
                {
                    this.txt_File.Text = openfile1.FileName;
                    if (!string.IsNullOrEmpty(openfile1.FileName))
                    {
                        con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + openfile1.FileName + ";Extended Properties=Excel 12.0;");
                        con.Open();
                        DataTable dt = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                        con.Close();

                        Combo_Sheet.Items.Clear();

                        for (int i = 0; i < dt.Rows.Count; i++)
                        {
                            String sheetName = dt.Rows[i]["TABLE_NAME"].ToString();
                                                       Combo_Sheet.Items.Add(sheetName);
                        }
                    }
                }
            }
            catch
            {
            }
        }

try
                {
                    OleDbDataAdapter oda = new OleDbDataAdapter("Select * from [" + Combo_Sheet.Text + "]", con);
                    DataTable dt = new DataTable();
                    oda.Fill(dt);
                    dataGridView1.DataSource = null;
                    dataGridView1.DataSource = dt;

                }
                catch
                {
                }

private void txt_Name_TextChanged(object sender, EventArgs e)
        {
            lb_Name.Text = txt_Name.Text.ToUpper();
        }

        private void txt_Part_TextChanged(object sender, EventArgs e)
        {
            lb_Part.Text = txt_Part.Text.ToUpper();
        }

        private void txt_Code_TextChanged(object sender, EventArgs e)
        {
            lb_Code.Text = txt_Code.Text.ToUpper();
            //generate barcode from textbox3
            //overwrite label 3 with code name
            lb_Code.Text = txt_Code.Text.ToUpper();
            string barCode = txt_Code.Text;
            try
            {
                Zen.Barcode.Code128BarcodeDraw brCode = Zen.Barcode.BarcodeDrawFactory.Code128WithChecksum;
                pictureBox1.Image = brCode.Draw(barCode, 40);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void btn_Print_Click(object sender, EventArgs e)
        {
            //show print dialog and print
            PrintDialog printDlg = new PrintDialog();
            if (printDlg.ShowDialog() == DialogResult.OK) printDocument1.Print();
            //printDocument1.Print();
        }


        private void printDocument1_PrintPage_1(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {
            //setup printing area
            Bitmap bm = new Bitmap(3000, 3000);
            Graphics gm = Graphics.FromImage(bm);
            bm.SetResolution(300, 300);
            gm.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            gm.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

            panel1.DrawToBitmap(bm, new Rectangle(0, 0, 3000, 3000));
            e.Graphics.DrawImage(bm, new Rectangle(0, 10, 900, 700));
        }