private void btnEdit_Click(object sender, EventArgs e)
        {
            if (lbOrders.SelectedItem != null)
            {
                var selectedOrder    = (Order)lbOrders.SelectedItem;
                var selectedCustomer = (Customer)cbCustomers.SelectedItem;

                if (selectedCustomer != null && selectedOrder != null)
                {
                    var oo = new OrderCreation(_loggedInEmployee, selectedCustomer, selectedOrder);
                    oo.Show();
                }
            }
        }
        private void btnNew_Click(object sender, EventArgs e)
        {
            var selectedCustomer = (Customer)cbCustomers.SelectedItem;

            if (selectedCustomer != null)
            {
                var oo = new OrderCreation(_loggedInEmployee, selectedCustomer);
                oo.ShowDialog();
            }

            else
            {
                MessageBox.Show("Please select a customer.");
            }
        }