Send extra info along to Authorize.net from Gravity Forms

functions.php

<?php
// Functions for apending form name to authorize.net invoice

 add_filter('gform_authorizenet_transaction_pre_capture', 'add_custom_field', 10, 5);

 function add_custom_field($transaction, $form_data, $config, $form, $entry)
 {
     if ($form['id'] == 3) {
         $donation_type = rgar($entry, '6');
         $honor_memory = rgar($entry, '10');
         $transaction->description = "Donation Type: $donation_type ---- Honor/Memory: $honor_memory";
     }
     return $transaction;
 }