Setting doc info variable in a plugin

global $content;
$e = &$modx->Event;

switch($e->name) {
  case 'OnBeforeDocFormSave':
  if ($content['parent'] == 32)
  {
    $content['richtext'] = 0;
  }
  break;

  default:
    return;
    break;
}

$table = $modx->db->config['table_prefix'] . 'site_content';
mysql_query("UPDATE $table SET richtext=0 WHERE id='$id'");

$e = &$modx->Event;

switch($e->name) {
  case 'OnDocFormSave':
  $pageinfo = $modx->getPageInfo($id,1,'parent');
  if ($pageinfo['parent'] == 32)
  {
    $table = $modx->db->config['table_prefix'] . 'site_content';
    mysql_query("UPDATE $table SET richtext=0 WHERE id='$id'");
  }
  break;

  default:
    return;
    break;
}