private void RegistrationButton_Click(object sender, RoutedEventArgs e)
        {
            int newID = 0;

            if (DB.GetListOfCustomers().Count > 0)
            {
                newID = DB.GetListOfCustomers()[DB.GetListOfCustomers().Count - 1].getPersonID() + 1;
            }
            Customer NewCustomer = new Customer(newID, FirstNameTextBox.Text, LastNameTextBox.Text, AddressTextBox.Text, PhoneTextBox.Text, EmailTextBox.Text);

            DB.AddCustomer(NewCustomer);
            MessageBox.Show("New customer has been added successfully with ID of " + newID.ToString());
            Content = new NewCustomOrderView(DB);
        }
 private void CreateCustomOrderButton_Click(object sender, RoutedEventArgs e)
 {
     Content = new NewCustomOrderView(DB);
 }