trubble on main index

<h2>Last Forum Posts</h2>
<table width=100% border=1 cellspacing=0 cellpadding=10><tr><td align=left>
<table class=main border=1 cellspacing=0 cellpadding=5>
   <?

include('http://host.com/punbb/extern.php?action=active');

?>

</table>
</table></div>

//
// Show recent discussions
//
if ($_GET['action'] == 'active' || $_GET['action'] == 'new')
{
       $order_by = ($_GET['action'] == 'active') ? 't.last_post' : 't.posted';
       $forum_sql = '';

       // Was any specific forum ID's supplied?
       if (isset($_GET['fid']) && $_GET['fid'] != '')
       {
               $fids = explode(',', trim($_GET['fid']));
               $fids = array_map('intval', $fids);

               if (!empty($fids))
                       $forum_sql = ' AND f.id IN('.implode(',', $fids).')';
       }

       // Any forum ID's to exclude?
       if (isset($_GET['nfid']) && $_GET['nfid'] != '')
       {
               $nfids = explode(',', trim($_GET['nfid']));
               $nfids = array_map('intval', $nfids);

               if (!empty($nfids))
                       $forum_sql = ' AND f.id NOT IN('.implode(',', $nfids).')';
       }

       // Should we output this as RSS?
       if (isset($_GET['type']) && strtoupper($_GET['type']) == 'RSS')
       {
               $rss_description = ($_GET['action'] == 'active') ? $lang_common['RSS Desc Active'] : $lang_common['RSS Desc New'];
               $url_action = ($_GET['action'] == 'active') ? '&action=new' : '';

               // Send XML/no cache headers
               header('Content-Type: text/xml');
               header('Expires: '.gmdate('D, d M Y H:i:s').' GMT');
               header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
               header('Pragma: public');

               // It's time for some syndication!
               echo '<?xml version="1.0" encoding="'.$lang_common['lang_encoding'].'"?>'."\r\n";
               echo '<!DOCTYPE rss PUBLIC "-//Netscape Communications//DTD RSS 0.91//EN" "http://my.netscape.com/publish/formats/rss-0.91.dtd">'."\r\n";
               echo '<rss version="0.91">'."\r\n";
               echo '<channel>'."\r\n";
               echo "\t".'<title>'.pun_htmlspecialchars($pun_config['o_board_title']).'</title>'."\r\n";
               echo "\t".'<link>'.$pun_config['o_base_url'].'/</link>'."\r\n";
               echo "\t".'<description>'.pun_htmlspecialchars($rss_description.' '.$pun_config['o_board_title']).'</description>'."\r\n";
               echo "\t".'<language>en-us</language>'."\r\n";

               // Fetch 15 topics
               $result = $db->query('SELECT t.id, t.poster, t.subject, t.posted, t.last_post, f.id AS fid, f.forum_name FROM '.$db->prefix.'topics AS t INNER JOIN '.$db->prefix.'forums AS f ON f.id=t.forum_id LEFT JOIN '.$db->prefix.'forum_perms AS fp ON (fp.forum_id=f.id AND fp.group_id=3) WHERE (fp.read_forum IS NULL OR fp.read_forum=1) AND t.moved_to IS NULL'.$forum_sql.' ORDER BY '.$order_by.' DESC LIMIT 15') or error('Unable to fetch topic list', __FILE__, __LINE__, $db->error());

               while ($cur_topic = $db->fetch_assoc($result))
               {
                       if ($pun_config['o_censoring'] == '1')
                               $cur_topic['subject'] = censor_words($cur_topic['subject']);

                       echo "\t".'<item>'."\r\n";
                       echo "\t\t".'<title>'.pun_htmlspecialchars($cur_topic['subject']).'</title>'."\r\n";
                       echo "\t\t".'<link>./punbb.php?page=viewtopic&id='.$cur_topic['id'].$url_action.'</link>'."\r\n";
                       echo "\t\t".'<description><![CDATA['.escape_cdata($lang_common['Forum'].': <a href="./punbb/viewforum?id='.$cur_topic['fid'].'">'.$cur_topic['forum_name'].'</a><br />'."\r\n".$lang_common['Author'].': '.$cur_topic['poster'].'<br />'."\r\n".$lang_common['Posted'].': '.date('r', $cur_topic['posted']).'<br />'."\r\n".$lang_common['Last post'].': '.date('r', $cur_topic['last_post'])).']]></description>'."\r\n";
                       echo "\t".'</item>'."\r\n";
               }

               echo '</channel>'."\r\n";
               echo '</rss>';
       }


       // Output regular HTML
       else
       {
               $show = isset($_GET['show']) ? intval($_GET['show']) : 15;
               if ($show < 1 || $show > 50)
                       $show = 15;

               // Fetch $show topics
               $result = $db->query('SELECT t.id, t.num_views, t.last_poster, t.num_replies, t.poster, t.posted, t.last_post, t.subject, f.forum_name FROM '.$db->prefix.'topics AS t INNER JOIN '.$db->prefix.'forums AS f ON f.id=t.forum_id LEFT JOIN '.$db->prefix.'forum_perms AS fp ON (fp.forum_id=f.id AND fp.group_id=3) WHERE (fp.read_forum IS NULL OR fp.read_forum=1) AND t.moved_to IS NULL'.$forum_sql.' ORDER BY '.$order_by.' DESC LIMIT '.$show) or error('Unable to fetch topic list', __FILE__, __LINE__, $db->error());

                   print("<table border=1 cellspacing=0 align=center class=main cellpadding=5><tr>".
"<td class=tabletitle align=left>Topic Title</td>".
"<td class=tabletitle align=left>Replies</td>".
"<td class=tabletitle align=left>Views</td>".
"<td class=tabletitle align=left>Author</td>".
"<td class=tabletitle align=left>Last Post</td>".
"</tr>");



               while ($cur_topic = $db->fetch_assoc($result))
               {
                       if ($pun_config['o_censoring'] == '1')
                               $cur_topic['subject'] = censor_words($cur_topic['subject']);

                       if (pun_strlen($cur_topic['subject']) > $max_subject_length)
                               $subject_truncated = pun_htmlspecialchars(trim(substr($cur_topic['subject'], 0, ($max_subject_length-5)))).' ?';
                       else
                               $subject_truncated = pun_htmlspecialchars($cur_topic['subject']);

                   $res = mysql_query("SELECT id FROM users WHERE username='$cur_topic[poster]'");
                   $row = @mysql_fetch_array($res);

                   $ras = mysql_query("SELECT id FROM users WHERE username='$cur_topic[last_poster]'");
                   $raw = @mysql_fetch_array($ras);

   print("<tr class=tableb><td style='padding-right: 5px'><a href=./punbb/viewtopic?id=".$cur_topic['id'].">$subject_truncated</a></td>".
"<td align=right>$cur_topic[num_replies]</td>" .
"<td align=right>$cur_topic[num_views]</td>".
"<td align=left><a href=userdetails.php?id=" . $row['id'] .">$cur_topic[poster]</a></td>" .
"<td align=left>" . gmdate('Y/m/d H:i:s', $cur_topic['last_post']) . " by <a href=userdetails.php?id=" . $raw['id'] .">$cur_topic[last_poster]</a></td>");

               }






print("</tr>");
// while



       }

       return;
}