private void buttonUserDelete_Click(object sender, EventArgs e)
        {
            if (listBoxUser.SelectedItem is Customer)
            {
                Customer customer = (Customer)listBoxUser.SelectedItem;

                if (customer.EmailAddress != FormController.CurrentCustomer.EmailAddress)
                {
                    if (Feedback.AskCustomerDelete() == DialogResult.Yes)
                    {
                        if (DBController.TryDeleteUser(customer))
                        {
                            UpdateTable();
                            Feedback.SuccessCustomersDelete();
                        }
                        else
                        {
                            Feedback.ErrorDatabaseCustomersDelete();
                        }
                    }
                }
                else
                {
                    Feedback.ErrorCustomersDeleteHimself();
                }
            }
            else
            {
                Feedback.ErrorNoSelectedItem();
            }
        }