Symfony1.4 writing criteria and return array

it's really so simple to write a criteria and return an array

$cri = new $Criteria();
$cri->add(TblNamePeer::ID,"value");
$cri_res = TblNamePeer::doSelect($cri);
$ret_val = array_unique($cri_res);
$this->ret_val = $ret_val;