private void btnPurchase_Click(object sender, EventArgs e)
        {
            if (_PC.cardCheck(txtCreditCard.Text))
            {
                DateTime Expiration = new DateTime(Convert.ToInt32(ddlExpYear.SelectedItem), Convert.ToInt32(ddlExpMonth.SelectedItem), 1);

                if (Expiration.AddMonths(1) > DateTime.Now)
                {
                    string orderNumber = "",
                           LastFour    = txtCreditCard.ToString().Substring(txtCreditCard.ToString().Length - 4, 4);;

                    Guid ticketNo = _PC.SubmitOrder
                                    (
                        ddlLevel.SelectedIndex,
                        Convert.ToChar(ddlSection.SelectedItem.ToString()),
                        Convert.ToInt32(ddlRow.SelectedItem.ToString()),
                        Convert.ToInt32(ddlSeat.SelectedItem.ToString()),
                        LastFour,
                        ref orderNumber
                                    );

                    PurchaseConfirm confirm = new PurchaseConfirm(orderNumber, ticketNo.ToString(), String.Format("XXXX-XXXX-XXXX-{0}", LastFour));

                    confirm.ShowDialog();
                }
            }
            else
            {
                MessageBox.Show("Invalid Credit Card. Check Card number and/or Expiration.");
            }
        }
        private void btnPurchase_Click(object sender, EventArgs e)
        {
            if (_PC.cardCheck(txtCreditCard.Text))
            {
                DateTime Expiration = new DateTime(Convert.ToInt32(ddlExpYear.SelectedItem), Convert.ToInt32(ddlExpMonth.SelectedItem), 1);

                if (Expiration.AddMonths(1) > DateTime.Now)
                {
                    string orderNumber = "", 
                    LastFour = txtCreditCard.ToString().Substring(txtCreditCard.ToString().Length - 4, 4);;

                    Guid ticketNo = _PC.SubmitOrder
                                    (
                                        ddlLevel.SelectedIndex,
                                        Convert.ToChar(ddlSection.SelectedItem.ToString()),
                                        Convert.ToInt32(ddlRow.SelectedItem.ToString()),
                                        Convert.ToInt32(ddlSeat.SelectedItem.ToString()),
                                        LastFour,
                                        ref orderNumber
                                    );

                    PurchaseConfirm confirm = new PurchaseConfirm(orderNumber, ticketNo.ToString(), String.Format("XXXX-XXXX-XXXX-{0}", LastFour));

                    confirm.ShowDialog();
                }
            }
            else
            {
                MessageBox.Show("Invalid Credit Card. Check Card number and/or Expiration.");
            }

        }