public function validateWrite(AgaviRequestDataHolder $rd)
	{
// any errors from .xml validation?
		if($this->getContainer()->getValidationManager()->hasErrors()) {
			return false;
		}

		$form = $rd->getParameter("form");
		$row = dbcall-goes-here($form['username'],$form['password']);

		// match?
		if( $row === false ) {
			$this->getContainer()->getValidationManager()->setError("form[username]",__('The username and password do not match anyone in our database'));
			return false;
		}

		// all good
		return true;
	}