private void button1_Click(object sender, EventArgs e)
        {
            c.fname         = namebox.Text.Trim();
            c.company       = cnamebox.Text.Trim();
            c.amount        = packagebox.Text.Trim();
            c.quantity      = Int32.Parse(quantitybox.Text.Trim());
            c.cost_price    = float.Parse(costbox.Text.Trim());
            c.selling_price = float.Parse(sellingbox.Text.Trim());
            c.barcode       = barcodebox.Text.Trim();
            c.exp_date      = dateTimePicker1.Value;
            c.mfg_date      = dateTimePicker2.Value;
            bool ok = cf.Insert(c);

            if (ok == true)
            {
                MessageBox.Show("PRODUCT ADDED SUCCESSFULLY!");
                DataTable dt = cf.Select();
                productlist.DataSource = dt;
                idbox.Text             = "";
                namebox.Text           = "";
                cnamebox.Text          = "";
                packagebox.Text        = "";
                quantitybox.Text       = "";
                costbox.Text           = "";
                sellingbox.Text        = "";
                barcodebox.Text        = "";
                DateTime localDate = DateTime.Now;
                dateTimePicker1.Value = localDate;
                dateTimePicker2.Value = localDate;
            }
            else
            {
                MessageBox.Show("FAILED TO ADD!");
            }
        }
        private void GenerateBill_Load(object sender, EventArgs e)
        {
            tcf.Clear();


            discountbox.Text = "0";
            amountbox.Text   = "0";

            SqlConnection conn = new SqlConnection(myconnstrng);

            try
            {
                string         query   = "select max(bill_id) from bill";
                SqlCommand     cmd     = new SqlCommand(query, conn);
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                conn.Open();
                billid = (int)cmd.ExecuteScalar();
                billid++;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            bidbox.Text = billid.ToString();

            DataTable dt = new DataTable();

            dt = sf.Select();
            stocklist.DataSource = dt;

            DataTable dt2 = new DataTable();

            dt2 = tcf.Select();
            cartlist.DataSource = dt2;

            //quantitybox;
            quantitybox.Text = quantity.ToString();
        }