Utilisation de preg_replace

<?PHP
define ('IN_SITE', 1);
include_once ('../includes/global.php');
$start = intval($_GET["start"]);
$limit = intval($_GET["limit"]);
$results = $db->query("SELECT a.auction_id, a.name,  a.description, a.max_bid,
    a.currency, a.buyout_price, a.start_price, a.max_bid, am.media_url, u.city, u.country, u.zip_code, c.name as country_name
    FROM " . DB_PREFIX . "auctions a
    LEFT JOIN " . DB_PREFIX . "auction_media am ON a.auction_id=am.auction_id AND am.media_type=1 AND am.upload_in_progress=0
    LEFT JOIN " . DB_PREFIX . "users u ON u.user_id=a.owner_id
    LEFT JOIN " . DB_PREFIX . "countries c ON u.country=c.id
    WHERE a.closed=0 AND a.active=1 AND a.approved=1 AND a.deleted=0
    GROUP BY a.auction_id
    ORDER BY a.auction_id LIMIT " . $start . ", " . $limit);
$xml_output = '<?xml version="1.0" encoding="iso-8859-1" standalone="no"?>
<!DOCTYPE yakaz SYSTEM "http://www.yakaz.com/yakaz.dtd" >
      <yakaz version="1.0">
      <ad-miscellaneous category="miscellaneous"> <!-- pour chaque autre annonce -->';
while ($row=@mysql_fetch_assoc($results)) {
   $auction_link = process_link('auction_details', array('name' => $row['name'], 'auction_id' => $row['auction_id']));
   if (!empty($row['media_url'])) {
      $picpath = '<img src="' . SITE_PATH . 'thumbnail.php?pic=' . $row['media_url'] . '&w=100">';
   }
   $description = preg_replace('!<[^>]+>!Us', '', html_entity_decode($row['description']));
   $xml_output .= '<what>
    <title>'.($row['name']).'</title>
                <description><![CDATA['.$description.']]></description>
                <ad-url>'.htmlentities($auction_link).'</ad-url>
                <picture-url>'.htmlentities($picpath).'</picture-url>
        <!-- logos proscrits - optionnel -->
                <price unit="euro">'.(($row['max_bid']>0)?$fees->display_amount($row['max_bid'], $row['currency']):$fees->display_amount($row['start_price'], $row['currency'])).'</price>
                <!-- caracteres collés, virgule pour décimales - si pas de prix, mettre 0 - optionnel -->
            </what>
            <where>
                <!-- optionnel -->
                <city-name>'.$db->add_special_chars($row['city']).'</city-name>
                <zip-code>'.$db->add_special_chars($row['zip_code']).'</zip-code>
                <country>'.$db->add_special_chars($row["country_name"]).'</country>
                <!-- code pays : FR pour la France -->
            </where>';
   }
   $xml_output .= '</ad-miscellaneous>
   </yakaz>';
file_put_contents ('monfichier.xml', $xml_output);
?>