public function executeLogin()
  {
   
    if ($this->getRequest()->getMethod() == sfRequest::GET)
    {
      $this->getRequest()->getParameterHolder()->set('referer_ref', $this->getRequest()->getReferer());
    }
    else
    {
 
      $referer_ref = $this->getRequestParameter('referer_ref');
      $referer_ref = (!$referer_ref) ? '@homepage': $referer_ref;
      return $this->redirect($referer_ref);
    }
  }

public function executeSignIn()
{
  if ($this->getRequest()->getMethod() != sfRequest::POST)
  {
    $this->getRequest()->getParameterHolder()->set('referer', $this->getRequest()->getReferer());
 
    return sfView::SUCCESS;
  }
  else
  {
    // redirect to last page
    return $this->redirect($this->getRequestParameter('referer', '@homepage'));
  }
}