Sub Categories

[Mythotical]

I have a script that displays categories and sub categories if a checkbox is selected during category addition.

The problem I'm having is getting them to display properly. Here is the code I use now to get 2 columns of categories only, sub cats I can't get to work and not sure how I would get to work.

PHP Code:

$number_cats = 0;
     $cats = $vbulletin->db->query("SELECT * FROM `" . TABLE_PREFIX . "xsdl_cats` WHERE sub_cat = '0'");

    while($category = $vbulletin->db->fetch_array($cats))
        {
                $cid = $category['cid'];
                $cname = $category['cat_name'];
                // $rating = round($entry['rating']);
                $description = $category['description'];
                $subcat = $category['sub_cat'];
                $file_loc = $category['file_loc'];
                $screen_loc = $category['screen_loc'];
 
                $query = $db->query_first("
                      SELECT COUNT(`dlid`) AS `total`
                    FROM `" . TABLE_PREFIX . "xs_downloads`
                    WHERE cat_id = " . $category['cid'] . "
                ");
 
                $count = $query['total'];
                $show['open_row'] = $number_cats++ %2 == 0;
                eval('$downloads_bit .= "' . fetch_template('xs_downloads_bit') . '";');
        } 


Any help much appreciated.
Steve M