//    first we check isset
                if(isset($_POST["csrftoken"])){
                    $csrftoken= $_POST["csrftoken"];
                    $decryptedToken = decrypt($csrftoken);
                    if($decryptedToken < time()) {
                        header("Location: error.php");
                        exit();
                    }
                }
                else{
                    header("Location: error.php");
                        exit();
                }