index.html <html> <head> <title>session demo</title> </head> <body> <form method=post action="login.php"> username:<input type="text" name="name"><br/> password:<input type="password" name="pwd"><br/> <input type="submit" value="submit"> </form> </body> </html> info.php <?php session_start(); if (session_is_registered(login)) { global $login; echo "hello,".$login['name']."<br/>"; echo "<a href=logout.php>exit</a><br/>"; } else { echo "False!!!!!<br/>"; exit; } ?> login.php <?php global $login; if ($_POST['name']!="zzl" || $_POST['pwd']!="111111") { echo "login false"; echo "<a href=index.htm>back</a>"; exit; } $login = array('name'=>$_POST['name'],'pwd'=>$_POST['pwd']); session_start(); session_register(login); echo "<a href=info.php>look</a><br/>"; echo "<a href=logout.php>exit</a><br/>"; ?> logout.php <?php session_start(); session_unregister(login); header("location:index.html"); ?> over