????：<?php //登錄 if(!isset($_POST['submit'])){     exit('非法訪問!'); } $username = htmlspecialchars($_POST['username']); $password =

<?php 

//登錄 

if(!isset($_POST['submit'])){ 

    exit('非法訪問!'); 

} 

$username = htmlspecialchars($_POST['username']); 

$password = MD5($_POST['password']); 

//包含數(shù)據(jù)庫連接文件 

include('conn.php'); 

//檢測用戶名及密碼是否正確 

$check_query = mysql_query("select userid from user_list where username='$username' and password='$password' limit 1"); 

if($result = mysql_fetch_array($check_query)){ 

    //登錄成功 

    session_start(); 

    $_SESSION['username'] = $username; 

    $_SESSION['userid'] = $result['userid']; 

    echo $username,' 歡迎你！進(jìn)入 <a href="my.php">用戶中心</a><br />'; 

    echo '點(diǎn)擊此處 <a href="login.php?action=logout">注銷</a> 登錄！<br />'; 

    exit; 

} else { 

    exit('登錄失?。↑c(diǎn)擊此處 <a href="javascript:history.back(-1);">返回</a> 重試'); 

} 

//注銷登錄 

if($_GET['action'] == "logout"){ 

    unset($_SESSION['userid']); 

    unset($_SESSION['username']); 

    echo '注銷登錄成功！點(diǎn)擊此處 <a href="login.html">登錄</a>'; 

    exit; 

} 

?? ???：天蓬老師?? ??：2019-04-08 09:36:13
???? ??：MD5($_POST['password']) , 這里的函數(shù)不要大寫, 盡管函數(shù)名是不區(qū)分大小寫的