PHP代码分页

<?php
include '../db/conn.php';
$sql="select * from str order by id";
$pageSize=10;
$page=$_REQUEST["page"];
if ($page<=0) {
$page=1;
}
$result=mysql_query($sql,$conn);
$num=mysql_num_rows($result);
$totalPage=ceil($num/$pageSize);
if ($page>=$totalPage) {
$page=$totalPage;
}
$pageNum=($page-1)*$pageSize;
$sql.=" limit $pageNum,$pageSize";
$result1 = mysql_query($sql,$conn);
?>
<center>

<style>
@IMPORT url("../css/css.css");
</style>

<script type="text/javascript">
function checkAll(){
var checkAll=document.getElementById("checkAll");
var idCheck=document.getElementsByName("idCheck[]");
for(var i=0;i<idCheck.length;i++){
idCheck[i].checked=checkAll.checked;