谢谢大家， >

Thank you everyone, got it working.

<?
//Start session
session_start();

$_SESSION['message'] = "";

//Include database connection details
require_once('global.php');


//Connect to mysql server
$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
if(!$link) {
    die('Failed to connect to server: ' . mysql_error());
}

//Select database
$db = mysql_select_db(DB_DATABASE);
if(!$db) {
    die("Unable to select database");
}

if(!empty($login) && !empty($password)) {

    $login = mysql_real_escape_string($_POST['login']);
    $password = mysql_real_escape_string($_POST['password']);

    $query = "SELECT * FROM tuser WHERE username = '$login' AND password = SHA('$password')";
    $data = mysql_query($query);

    if($data) {
        if (mysql_num_rows($data) == 1 ) {
            $row = mysql_fetch_assoc($data);
            $_SESSION['userid'] = $row['userid'];
            $_SESSION['username'] = $row['username'];
            $_SESSION['message'] = "Welcome,&nbsp;" . $_SESSION['username'];
            header('Location: member.php');
            exit();
        }
        else {
            $_SESSION['message'] = "Please enter a valid username or password";
            header('Location: error.php');
            exit();
        }

    }
    else {
        die("Query failed");
    }

}
else {
    $_SESSION['message'] = "Please enter a username or password";
    header('Location: error.php');
    exit();
}


?>