protected void Pay(object sender, EventArgs e) { if (Valid()) { CreditCardValidator cardValidator = new CreditCardValidator(); if (cardValidator.ValidMod10(CardNumber.Text)) { ErrorMsg.Text = ""; int userId = (int)Session["id"]; int screeningId = (int)Session["screening_id"]; List <int> seats = (List <int>)Session["seats"]; foreach (int seat in seats) { Database.InsertTicket(screeningId, seat, userId); } Response.Redirect("Default.aspx"); } else { ErrorMsg.Text = "Invalid input"; } } else { ErrorMsg.Text = "Invalid input"; } }