Pagination

I'm trying to pagination...
I don't like YII way then I'm tryign to make one by myself

This is what I've done, but it's not showing any item...
when I delete the limit then it's show all the items

$page = ($page < 1 || intval($page) != $page) ? 1 : $page;
$per_page = 12;
$start_form = ($page-1)*$per_page;
$items = Item::model()->findAllByAttributes(array('p_catgory'=>$p),array('order'=>'id DESC','limit'=>"$start_form,$per_page"));