分页程序有一个错误，但我找了两天都没发现哪里有问题。帮我看看

<?   print"<tr valign=top><TH align=center>书名</TH><TH align=center>作者</TH><TH
 align=center>出版社</TH><TH align=center>页数</TH><TH align=center>价格</TH><TH 
align=center>action</TH></TR>\n";
      if(isset($which)&&isset($from)&&isset($total)){
  $db=@mysql_connect("SIMBA","simba","19811116");
  if($db==false){
  print"connect failed!";
  exit();
  }
  $to=($total<($from+$MAXROWS))?($total-$from):$MAXROWS;
  $query="select isdn,bookname,author,bookconcern,realprice  from books wher
e class=$which order by publishdate limit $from+0,$to;";
  $res=@mysql_db_query("bookseller",$query,$db);
  if($res==false){
  print"Query failed!";
  exit();
  }
  if($total!=0){
  print"显示记录".($from+0)."-";
  print $to+$from-1;
  print"(总共 $total)\n<TR>";   for($i=0;$i<mysql_num_rows($res);$i++){
  $row=mysql_fetch_row($res);
 
                      for($j=2;$j<7;$j++){
  print"<TD align=center>$row[$j]</TD>";   }
  print"<TD align=center>";
     }
print"<tr><td colspan=7 align=center>";
print"<A href=\"$PHP_SELF?from=0&total=$total\">";
print"首页</A>&nbsp";
if($from>=2*$MAXROWS){
print"<A href=\"$PHP_SELF?from=";
print($from-$to)."&total=$total\">上一页</A>&nbsp";
}
if(($from+$to)<$total){
print"<A href=\"$PHP_SELF?from=";
print($from+$to)."&total=$total\">下一页</A>&nbsp";
}
if(($total>$MAXROWS)){
    print"<A href=\"$PHP_SELF?from=";
print($total-$total%$MAXROWS);
print"&total=$total\">末页</A>";
}
print"</td></tr>\n";

}?>
                          </tbody>
</table>                    </td>
                  </tr>
 </table>
  </td>
       </tr>
    </tbody>
  </table>
</body>
</html>