Joomla 3 external registration script

jRegistration.php

<?php
  define( '_JEXEC', 1 );
  define('JPATH_BASE', dirname(__FILE__) );
  define( 'DS', DIRECTORY_SEPARATOR );
  
  /* Required Files */
  require_once ( JPATH_BASE .DS.'includes'.DS.'defines.php' );
  require_once ( JPATH_BASE .DS.'includes'.DS.'framework.php' );

  $app = JFactory::getApplication('site');
  $app->initialise();
  
  require_once(JPATH_BASE.DS.'components'.DS.'com_users'.DS.'models'.DS.'registration.php');
  //not necessary
  //require_once(JPATH_BASE.DS.'libraries'.DS.'joomla'.DS.'application'.DS.'component'.DS.'helper.php';
  
  $model = new UsersModelRegistration();
  jimport('joomla.mail.helper');
  jimport('joomla.user.helper');

  $language = JFactory::getLanguage();
  $language->load('com_users', JPATH_SITE);

  $username = 'adam';
  $name = 'adam24';
  $email = 'adam@mailinator.com';
  $password = 'adam';
  $data = array( 'username' => $username,
    'name' => $name,
    'email1' => $email,
    'password1' => $password, // First password field
    'password2' => $password, // Confirm password field
    'block' => 0 );
    
  echo $model->register($data);

  if (version_compare(PHP_VERSION, '5.3.1', '<')) {
    die('Your host needs to use PHP 5.3.1 or higher to run this version of Joomla!');
  }
?>