Checking the password using hashes and salt

$check = hash('md5', $salt.$_POST['pass']);
$stmt = $pdo->prepare('SELECT user_id, name FROM users
    WHERE email = :em AND password = :pw');
$stmt->execute(array( ':em' => $_POST['email'], ':pw' => $check));
$row = $stmt->fetch(PDO::FETCH_ASSOC);
 
 
 
 
if ( $row !== false ) {
    $_SESSION['name'] = $row['name'];
    $_SESSION['user_id'] = $row['user_id'];
    // Redirect the browser to index.php
    header("Location: index.php");
    return;