//Opens the email window and fills it with the data for the selected customer so they can be emailed.
 private void Email_Click(object sender, RoutedEventArgs e)
 {
     if (CustomerList.SelectedItem != null)
     {
         //Fetch that row and store it as a CustomerViewmodel so it is easy to manipulate the data.
         CustomerViewmodel SelectedCustomer = (CustomerViewmodel)CustomerList.SelectedItem;
         EditFirstnameField.Text = SelectedCustomer.Firstname;
         EditLastnameField.Text  = SelectedCustomer.Lastname;
         EditEmailField.Text     = SelectedCustomer.Email;
         EmailWindow emailWindow = new EmailWindow();
         emailWindow.Show();
         EmailWindow.SetContent(SelectedCustomer.Email, SelectedCustomer.Firstname, SelectedCustomer.Lastname);
     }
     else
     {
         MessageBox.Show("No item selected.", "Invalid", MessageBoxButton.OK, MessageBoxImage.Warning);
     }
 }
 //Loads the details of the selected customer into the edit box so they can be edited by the user.
 private void Manage_Click(object sender, RoutedEventArgs e)
 {
     if (CustomerList.SelectedItem != null)
     {
         //Fetch that row and store it as a PriceItem so it is easy to manipulate the data.
         CustomerViewmodel SelectedCustomer = (CustomerViewmodel)CustomerList.SelectedItem;
         EditID.Text              = "" + SelectedCustomer.ID + "";
         EditFirstnameField.Text  = SelectedCustomer.Firstname;
         EditLastnameField.Text   = SelectedCustomer.Lastname;
         EditEmailField.Text      = SelectedCustomer.Email;
         EditAddressOneField.Text = SelectedCustomer.AddressOne;
         EditAddressTwoField.Text = SelectedCustomer.AddressTwo;
         EditCityField.Text       = SelectedCustomer.City;
         EditCountyField.Text     = SelectedCustomer.County;
         EditPostcodeField.Text   = SelectedCustomer.Postcode;
         EditCountryField.Text    = SelectedCustomer.Country;
         EditMobileField.Text     = SelectedCustomer.Mobile;
     }
     else
     {
         MessageBox.Show("No item selected.", "Invalid", MessageBoxButton.OK, MessageBoxImage.Warning);
     }
 }