magento 1.9, how sort products by stock

i have this code $product_model = Mage::getModel(‘catalog/product’)->getCollection() ->setPageSize(5) ->setOrder(‘entity_id’, ‘DESC’) ->addAttributeToFilter(‘attribute_set_id’, array(‘in’ => array(‘4′, ’12’))) ->addAttributeToFilter(‘price’, array(‘gteq’=>80)) ->joinField( ‘qty’, ‘cataloginventory/stock_item’, ‘qty’, ‘product_id=entity_id’, ‘.stock_id=1’, ‘left’ ); $product_model->getSelect()->joinLeft( array(‘_inventory_table’ => $product_model->getTable(‘cataloginventory/stock_item’)), “_inventory_table.product_id = e.entity_id”, array(‘is_in_stock’, 0) ); I want to get all the products that out_of_stock How can this be done in my request? and how can…