private void btnAdd_Click(object sender, EventArgs e)
        {
            FrmCreditCard form = new FrmCreditCard();

            form.ShowDialog();
            creditCards = new BindingList <CreditCard>(ctr.List().ToList());
            dtvCreditCard.DataSource = creditCards;
        }
        private void btnEdit_Click(object sender, EventArgs e)
        {
            CreditCard    editCard = (CreditCard)dtvCreditCard.SelectedRows[0].DataBoundItem;
            FrmCreditCard form     = new FrmCreditCard();

            form.setCreditCard(editCard);
            if (form.ShowDialog() == DialogResult.OK)
            {
                creditCards.Remove(editCard);
                editCard = form.getCreditcard();
                ctr.Save(editCard);
                creditCards.Add(editCard);
            }
        }