PHP search plus pagination

$wherelist=array();
$urlist=array();
if(!empty($_GET['title']))
{
$wherelist[]=" title like '%".$_GET['title']."%'";
$urllist[]="title=".$_GET['title'];
 
}
if(!empty($_GET['keywords']))
{
$wherelist[]=" keywords like '%".$_GET['keywords']."%'";
$urllist[]="keywords=".$_GET['keywords'];
}if(!empty($_GET['author']))
{
$wherelist[]=" author like '%".$_GET['author']."%'";
$urllist[]="author=".$_GET['author'];
}
$where="";
if(count($wherelist)>0)
{
$where=" where ".implode(' and ',$wherelist);
$url='&'.implode('&',$urllist);
}
//分页的实现原理
//1.获取数据表中总记录数
$sql="select count(*) from news $where ";
$result=mysql_query($sql);
$totalnum=mysql_num_rows($result);
//每页显示条数
$pagesize=5;
//总共有几页
$maxpage=ceil($totalnum/$pagesize);
$page=isset($_GET['page'])?$_GET['page']:1;
if($page <1)
{
$page=1;
}
if($page>$maxpage)
{
$page=$maxpage;
}
$limit=" limit ".($page-1)*$pagesize.",$pagesize";
$sql1="select * from news {$where} {$limit}";
 
//$sql1="select * from news {$where} {$limit}";
$res=mysql_query($sql1);
 
?>
<form action="searchpage.php" method="get">
标题：<input type="text" name="title" value="<?php echo $_GET[&#39;title&#39;]?>" size="8">
关键字<input type="text" name="keywords" value="<?php echo $_GET[&#39;keywords&#39;]?>" size="8">
作者：<input type="text" name="author" value="<?php echo $_GET[&#39;author&#39;]?>" size="8">
    <input type="button" value="查看全部" onclick="window.location=&#39;searchpage.php&#39;">
    <input type="submit" value="搜索">
</form>
 
<table border="1" width="1000" align="center">
    <tr>
        <td>编号</td>
        <td>标题</td>
        <td>关键字</td>
        <td>作者</td>
        <td>日期</td>
        <td>内容</td>
    </tr>
<?php while($row= mysql_fetch_assoc($res)){?>
<tr>
            <td><?php echo $row[&#39;id&#39;] ?></td>
            <td><?php echo $row[&#39;title&#39;] ?></td>
            <td><?php echo $row[&#39;keywords&#39;] ?></td>
            <td><?php echo $row[&#39;author&#39;] ?></td>
            <td><?php echo date("Y-m-d H:i:s",$row[&#39;addtime&#39;]) ?></td>
            <td><?php echo $row[&#39;content&#39;] ?></td>
        </tr>
<?php }?>
<tr>
        <td colspan="6">
<?php
            echo " 当前{$page}/{$maxpage}页 共{$totalnum}条";
echo " <a href=&#39;searchpage.php?page=1{$url}&#39;>首页</a> ";
echo "<a href=&#39;searchpage.php?page=".($page-1)."{$url}&#39;>上一页</a>";
echo "<a href=&#39;searchpage.php?page=".($page+1)."{$url}&#39;>下一页</a>";
echo " <a href=&#39;searchpage.php?page={$maxpage}{$url}&#39;>尾页</a> ";
 
?>
</td>
    </tr>
</table>