Add sort by in specials page

[mcsehack]

Help!!!
How to add sort by in specials page,Please see our page and code as below, we added it,but the sort by result is wrong.Thanks in advance.
http://www.formydeal.com/specials.html

code:
<?php
/**
* Specials
*
* @package page
* @copyright Copyright 2003-2007 Zen Cart Development Team
* @copyright Portions Copyright 2003 osCommerce
* @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
* @version $Id: main_template_vars.php 6912 2007-09-02 02:23:45Z drbyte $
*/

if (MAX_DISPLAY_SPECIAL_PRODUCTS > 0 ) {
$specials_query_raw = "SELECT p.products_id, p.products_image, pd.products_name,
p.master_categories_id
FROM (" . TABLE_PRODUCTS . " p
LEFT JOIN " . TABLE_SPECIALS . " s on p.products_id = s.products_id
LEFT JOIN " . TABLE_PRODUCTS_DESCRIPTION . " pd on p.products_id = pd.products_id )
WHERE p.products_id = s.products_id and p.products_id = pd.products_id and p.products_status = '1'
AND s.status = 1
AND pd.language_id = :languagesID
ORDER BY s.specials_date_added DESC";

$specials_query_raw = $db->bindVars($specials_query_raw, ':languagesID', $_SESSION['languages_id'], 'integer');
$specials_split = new splitPageResults($specials_query_raw, MAX_DISPLAY_SPECIAL_PRODUCTS);
$specials = $db->Execute($specials_split->sql_query);
$row = 0;
$col = 0;
$list_box_contents = array();
$title = '';

$num_products_count = $specials->RecordCount();
if ($num_products_count) {
if ($num_products_count < SHOW_PRODUCT_INFO_COLUMNS_SPECIALS_PRODUCTS || SHOW_PRODUCT_INFO_COLUMNS_SPECIALS_PRODUCTS==0 ) {
$col_width = floor(100/$num_products_count);
} else {
$col_width = floor(100/SHOW_PRODUCT_INFO_COLUMNS_SPECIALS_PRODUCTS);
}

$list_box_contents = array();
while (!$specials->EOF) {

$products_price = zen_get_products_display_price($specials->fields['products_id']);
$specials->fields['products_name'] = zen_get_products_name($specials->fields['products_id']);
$list_box_contents[$row][$col] = array('params' => 'class="specialsListBoxContents"' . ' ' . 'style="width:' . $col_width . '%;"',
'text' => '<a href="' . zen_href_link(zen_get_info_page($specials->fields['products_id']), 'cPath=' . zen_get_generated_category_path_rev($specials->fields['master_categories_id']) . '&products_id=' . $specials->fields['products_id']) . '">' . (($specials->fields['products_image'] == '' and PRODUCTS_IMAGE_NO_IMAGE_STATUS == 0) ? '' : zen_image(DIR_WS_IMAGES . $specials->fields['products_image'], $specials->fields['products_name'], SMALL_IMAGE_WIDTH, SMALL_IMAGE_HEIGHT) . '</a>') . '<br /><a href="' . zen_href_link(zen_get_info_page($specials->fields['products_id']), 'cPath=' . zen_get_generated_category_path_rev($specials->fields['master_categories_id']) . '&products_id=' . $specials->fields['products_id']) . '">' . $specials->fields['products_name'] . '</a><br />' . $products_price);
$col ++;
if ($col > (SHOW_PRODUCT_INFO_COLUMNS_SPECIALS_PRODUCTS - 1)) {
$col = 0;
$row ++;
}
$specials->MoveNext();
}
require($template->get_template_dir('tpl_specials_default.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_specials_default.php');
}
}
?>

<?php
/**
* Specials
*
* @package page
* @copyright Copyright 2003-2006 Zen Cart Development Team
* @copyright Portions Copyright 2003 osCommerce
* @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
* @version $Id: header_php.php 3000 2006-02-09 21:11:37Z wilt $
*/

require(DIR_WS_MODULES . zen_get_module_directory('require_languages.php'));
$breadcrumb->add(NAVBAR_TITLE);
if (MAX_DISPLAY_SPECIAL_PRODUCTS > 0 ) {
$disp_order_default = PRODUCT_ALL_LIST_SORT_DEFAULT;
require(DIR_WS_MODULES . zen_get_module_directory(FILENAME_LISTING_DISPLAY_ORDER));
$order_by = isset($order_by) ? $order_by : 'ORDER BY s.specials_date_added DESC';
if (MAX_DISPLAY_SPECIAL_PRODUCTS > 0 ) {
$listing_sql = "SELECT p.products_id, p.products_image, pd.products_name,
p.master_categories_id
FROM (" . TABLE_PRODUCTS . " p
LEFT JOIN " . TABLE_SPECIALS . " s on p.products_id = s.products_id
LEFT JOIN " . TABLE_PRODUCTS_DESCRIPTION . " pd on p.products_id = pd.products_id )
WHERE p.products_id = s.products_id and p.products_id = pd.products_id and p.products_status = '1'
AND s.status = 1
AND pd.language_id = :languagesID
ORDER BY s.specials_date_added DESC";

$listing_sql = $db->bindVars($listing_sql, ':languagesID', $_SESSION['languages_id'], 'integer');
//check to see if we are in normal mode ... not showcase, not maintenance, etc
$show_submit = zen_run_normal();

$define_list = array('PRODUCT_LIST_MODEL' => PRODUCT_LIST_MODEL,
'PRODUCT_LIST_NAME' => PRODUCT_LIST_NAME,
'PRODUCT_LIST_MANUFACTURER' => PRODUCT_LIST_MANUFACTURER,
'PRODUCT_LIST_PRICE' => PRODUCT_LIST_PRICE,
'PRODUCT_LIST_QUANTITY' => PRODUCT_LIST_QUANTITY,
'PRODUCT_LIST_WEIGHT' => PRODUCT_LIST_WEIGHT,
'PRODUCT_LIST_IMAGE' => PRODUCT_LIST_IMAGE);

/* ,
'PRODUCT_LIST_BUY_NOW' => PRODUCT_LIST_BUY_NOW);
*/
asort($define_list);
reset($define_list);
$column_list = array();
foreach ($define_list as $key => $value)
{
if ($value > 0) $column_list[] = $key;
}
}
}
?>