private void btnAddPaymentType_Click(object sender, EventArgs e)
        {
            if (!string.IsNullOrEmpty(TBoxPType.Text))
            {
                if (checkForSameness())
                {
                    MessageBox.Show("This payment type is already added!");
                }
                else
                {
                    pType             = new cPaymentTypeOperations();
                    pType.paymentType = TBoxPType.Text;

                    pType.sqlQuery = "insert into PAYMENTTYPE (explanation) values (@PType)";
                    pType.addNewPType();

                    MessageBox.Show("Payment type is added!");
                    TBoxPType.Clear();
                }
            }
            else
            {
                MessageBox.Show("Please write a payment type!");
            }
        }
        void listAllPaymentTypes()
        {
            pType          = new cPaymentTypeOperations();
            pType.sqlQuery = "select explanation from PAYMENTTYPE";
            pType.showPaymentTypes();

            fillLView();
        }
        void fillCBoxPType()
        {
            pType = new cPaymentTypeOperations();
            pType.sqlQuery = "select explanation as 'Payment Type' from PAYMENTTYPE";
            pType.showPaymentTypes();

            CBoxPType.DataSource = pType.dataTable;
            CBoxPType.DisplayMember = "Payment Type";
        }
        private bool checkForSameness()
        {
            pType             = new cPaymentTypeOperations();
            pType.paymentType = TBoxPType.Text;

            pType.sqlQuery = "select explanation from PAYMENTTYPE";

            return(pType.checkIsPTypeAlive());
        }