php中读取数据库里记录并分页

<?php
//连接数据库
$db=mysql_connect("localhost","root","root");
mysql_select_db("gaoge",$db);
//设定每一页显示的记录数
$pagesize=3;

//取得记录总数，计算总页数用
$res=mysql_query("select count(*) from image " ,$db);
$myrow = mysql_fetch_array($res);
//$myrow[o]为数据库里总记录数目之和
$numrows=$myrow[0];
//echo "total num is:";
//echo $numrows;
// echo '<br>';
//计算总页数
$pages=intval($numrows/$pagesize);

if ($numrows%$pagesize)
$pages++;
// echo "total pages is:";
//echo $pages;
//echo '<br/>';
//判断页数设置与否，如无则定义为首页

if (isset($_GET['page'])){
//echo "page exist";
$page = $_GET['page'];
//echo "enter if ";
}
else{
//echo "page not exist";
$page = 1;
}

//echo "page is:" ;
// echo $page;
// echo '<br/>';
//计算记录偏移量
$offset=$pagesize*($page-1);
// echo "offset is:" ;
echo $offset;
//取记录
$res=mysql_query("select * from image order by id desc limit $offset,$pagesize" ,$db);
//循环显示记录
if ($myrow = mysql_fetch_array($res))
{
$i=0;
?>
<table cellspacing=0 bordercolordark=#FFFFFF width="95%" bordercolorlight=#000000 border=1 align="center" cellpadding="2">
<tr bgcolor="#6b8ba8" style="color:FFFFFF">
<td width="10%" align="center" valign="bottom" height="19">ＩＤ</td>
<td width="10%" align="center" valign="bottom">图片名称</td>
<td width="5%" align="center" valign="bottom">上传人姓名</td>
<td width="%40" align="center" valign="bottom">上传时间</td>
<td width="60%" align="center" valign="bottom">图片效果</td>

</tr>
<?php
do {
$i++;
?>
<tr>
<td width="5%" bgcolor="#E6F2FF"><?php echo $i;?></td>
<td width="10%" bgcolor="#E6F2FF"><?php echo $myrow[1];?> </td>
<td width="5%" bgcolor="#E6F2FF"><?php echo $myrow[2];?> </td>
<td width="40%" bgcolor="#E6F2FF"><?php echo $myrow[3];?> </td>
<td width="60%" bgcolor="#E6F2FF"><img src="<?=$myrow[4];?>"/></td>
</tr>
<?php
}
while ($myrow = mysql_fetch_array($res));
echo "</table>" ;
}
//显示总页数
echo "<div align='center'>共有".$pages."页(".$page."/".$pages.")<br>";
//显示分页数
for ($i=1;$i<=$pages;$i++)
echo "<a href='pages.php?page=".$i."'>第".$i ."页</a> ";
//echo "page is:";
//echo "$page";

// echo "<br>";
//显示转到页数
echo "<form action='pages.php' method='post'> ";
//计算首页、上一页、下一页、尾页的页数值
$first=1;
$prev=$page-1;
$next=$page+1;
$last=$pages;

echo "<a href='pages.php?page=".$first."'>首页</a> ";
//echo "page is:";
//echo "$page";
echo "<a href='pages.php?page=".$prev."'>上一页</a> ";

echo "<a href='pages.php?page=".$next."'>下一页</a> ";
echo "<a href='pages.php?page=".$last."'>尾页</a> ";

echo "</form>";
echo "</div>";
?>