How to add business logic on form save

DocumentIdentificationForm.php

<?php
class DocumentIdentificationForm extends DocumentForm
{
  protected function doUpdateObject($values)
  {
    parent::doUpdateObject($values);

    if ($values['author_id'])
      $this->getObject()->setStatusId(Doctrine_Core::getTable('Status')->getIdentifiedStatus());
    else
      $this->getObject()->setStatusId(Doctrine_Core::getTable('Status')->getUnkownStatus());
  }
}