Problems with querys

[eluser]mikeyhell[/eluser]
I'm trying to write an app that returns the previous and next rows based on what the current query is and it's not working? The way I understand it, if you return a query w/ the row #4 the next row would be #5 and previous would be #3. Instead I get the same row returned for all 3.

$this->db->where('id', $id);
$query= $this->db->get('entries');
$data['next']= $query->next_row();
$data['last']= $query->previous_row();

??