public function action_email()
{
$session = Session::instance();
$bill_id = $this->request->param('options');
$bill = new Bill($bill_id);
if ($bill->send_mail()) {
$session->set('message', 'Mail sent for bill #' . $bill_id);
} else {
$session->set('error', 'Mail for bill #' . $bill_id . ' failed!');
}
$this->redirect();
// if email sent then update bills.invoice_sent with CURRENT_TIMESTAMP
}
