倒计时练习

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script src="../jquery-1.11.2.min.js"></script>
<style type="text/css">
*{ margin:0px auto; padding:0px}
#djs{ 300px; height:100px}
#fen{ float:left; 100px; height:100px; text-align:center; line-height:100px; vertical-align:middle; font-size:36px; font-weight:bold; font-family:"微软雅黑"; color:#9C9}
#miao{ float:left; 100px; height:100px; text-align:center; line-height:100px; vertical-align:middle; font-size:36px; font-weight:bold; font-family:"微软雅黑"; color:#9C9}
#zz{ float:left; 100px; height:100px; text-align:center; line-height:100px; vertical-align:middle; font-size:36px; font-weight:bold; font-family:"微软雅黑"; color:#9C9}
</style>
</head>

<body>
<?php
session_start();
//设置倒计时时间
	$attr=array();
	if(empty($_SESSION["djs"]))
	{
		$attr=array("fen"=>1,"miao"=>00);
		$_SESSION["djs"]=$attr;
	}
	else
	{
		$attr=$_SESSION["djs"];	
	}
//开始倒计时 用JS控制
?>
<div id="djs">
	<div id="fen"><?php echo $attr["fen"]; ?></div>
    <div id="zz">:</div>
    <div id="miao"><?php echo $attr["miao"]; ?></div>
</div>
</body>
<script type="text/javascript">
$(document).ready(function(e) {
    window.setInterval("ShowTime()",1000);//间隔执行
});
function ShowTime()
{
	$.ajax({
		url:"djschuli.php",
		dataType:"TEXT",
		success: function(data){
				if(data.trim()=="OVER")
				{
					$("#djs").text("倒计时结束");
				}
				else
				{
					var lie=data.trim().split("|");
					$("#fen").text(lie[0]);
					$("#miao").text(lie[1]);
				}
			}
		});	
}
</script>
</html>

<?php
session_start();
$attr=$_SESSION["djs"];
$fen=$attr["fen"];
$miao=$attr["miao"];
if($fen==0 && $miao==0)
{
	echo"OVER";
	exit();	
}
if($miao==0)
{
	$attr["miao"]=59;
	$attr["fen"]=$attr["fen"]-1;	
}
else
{
	$attr["miao"]=$attr["miao"]-1;	
}
$_SESSION["djs"]=$attr;
echo "{$attr['fen']}|{$attr['miao']}";