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<?php
session_start();
header("Content-type:text/html;charset=utf-8");
$link = mysqli_connect('localhost','root','root','mybbs');//鏈接數(shù)據(jù)庫
mysqli_set_charset($link,'utf8'); //設(shè)定字符集
$username=$_POST['username'];
$password=md5($_POST['password']);
    if($username==''){
        echo "<script>alert('請(qǐng)輸入用戶名');location='" . $_SERVER['HTTP_REFERER'] . "'</script>";
        exit;
    }
    if($password==''){
        echo "<script>alert('請(qǐng)輸入密碼');location='" . $_SERVER['HTTP_REFERER'] . "'</script>";
        exit;
    }
$sql="select id,username,password from member where username= $username";      //從數(shù)據(jù)庫查詢信息
$que=mysqli_query($link,$sql);
$row=mysqli_fetch_array($que);
if($row){
    if($password !=($row['password']) || $username !=$row['username']){
        echo "<script>alert('密碼錯(cuò)誤，請(qǐng)重新輸入');location='login.html'</script>";
        exit;
    }
    else{
        $_SESSION['username']=$row['username'];
        $_SESSION['id']=$row['id'];
        echo "<script>alert('登錄成功');location='index.php'</script>";
    }
}else{
    echo "<script>alert('您輸入的用戶名不存在');location='login.html'</script>";
    exit;
};
?>