PHP login script

<?php


    require_once('../store.rbxtv.com/wordpress/wp-includes/user.php');
        require_once('dbConnect.php');
    if($_SERVER['REQUEST_METHOD']=='POST'){
        //Getting values
        $username = '';
                $password = '';
                $user = null;
$result = wp_authenticate_username_password($user, $username, $password);
if (is_wp_error($result)) {

echo 'not authenticated';

} else {

echo 'authenticated';

}
        mysqli_close($con);
    }