//delete customer
        private void btnDelete_Click(object sender, RoutedEventArgs e)
        {
            Customer bCustomer = new Customer();

            if (txtBoxfindID.Text != "")
            {
                int custID = Convert.ToInt16(txtBoxfindID.Text);

                bCustomer = dataLayerSingleton.findCustomer(custID);


                if (lstBoxBookings.Items.Count == 0)
                {
                    dataLayerSingleton.deleteCustomer(custID);
                }
                else
                {
                    MessageBox.Show("You can't delete a customer if it has bookings");
                    return;
                }

                //clear boxes
                txtBoxfindID.Clear();
                lblShowName.Content    = "";
                lblShowAddress.Content = "";

                //remove customer from listbox
                lstBoxCustomers.Items.Remove(custID);

                btnDelete.IsEnabled = false;
                btnModify.IsEnabled = false;

                MessageBox.Show("Don't forget to UPDATE INFORMATION before going to next page.");
            }
            else
            {
                MessageBox.Show("Nah nah");
            }
        }