如何使用php创建包含会话cookie的注销页面？

我想创建一个logout.php，以便它记住login.php中的用户名

我想使用$\u GET方法，以便它从登录中获取会话用户名，当我们注销时，cookie会话将注销。如果没有设置cookie会话，则会出现一个错误，说明没有人登录，所以log gout无法工作

php对用户进行登录并设置cookie，我从浏览器设置中检查了cookie

login.php

<?php 

require"connection.php";
if (!isset($_POST['submit'])){
    $user = $_POST['username']; 
    $password = $_POST['password'];  

  if ($user){ 
        if ($password){ 

setcookie('username', '$user', time()+3600); 
setcookie('password', '$password', time()+3600);       

          //make sure login info correct
            $query = mysql_query("SELECT * FROM users WHERE username = '$user'"); 
                $numrows = mysql_num_rows($query); 

            if ($numrows == 1) {
                $row = mysql_fetch_assoc($query); 
                 $dbuser = $row['username']; 
                 $dbpass = $row['password']; 

        echo '<script type="text/javascript">alert("Welcome, '.$user.'. A cookie session  has been created.");</script>'; 
        }else{echo "Please enter valid username or password";}
        }else {echo "Your password didn't match. Please try again";}
        }else {echo "Your username didn't match. Please try again";}
        }else {echo "Please enter username and password";}
?> 

---

试试这样的方法

if(isset($_COOKIE['username']) && !empty($_COOKIE['username'])) {
    // Bye $_COOKIE['username'], you are logged out.
    setcookie('username', '', time() - 3600);
} else {
    // no user logged in
}

只需在注销页面上检查会话，若未设置特定会话，则可以给出错误。您不需要使用会话cookie…并且在将POST数据插入SQL之前不要忘记转义POST数据。您是否知道如何回显已登录的用户名，例如说：“再见，Alex，您已注销”。我们需要$\u GET命令吗？