利用cookie post登陆后台模板

<?
$pwd='123456';
if(isset($_COOKIE['pwd'])){
echo '欢迎管理员来到后台';
}elseif($_POST['pwd'] == $pwd)
{
setcookie("pwd", "mm", time()+3600);
echo '密码正确<a href="ck.php">点击刷新</a>';
}elseif($_POST['submit']){
echo '请不要非法闯入';
}else{
echo '<form action="ck.php" method="POST">密码:<input type="text" name="pwd"><br><input type="submit" name="submit" value="提交"></from>';}
?>