logout problems laravel 5

I can not get out of my application, I'm using the auth out of box login for laravel 5, but when I get out of my account, I'm not successful. Can someone help me ?

this is my app.blade.php ->

                    @guest
                        <li><a href="">Login</a></li>
                        <li><a href="">Register</a></li>
                    @else
                        <li class="dropdown">
                            <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false" aria-haspopup="true" v-pre>
                                 <span class="caret"></span>
                            </a>

                            <ul class="dropdown-menu">
                                <li>
                                    <a href=""
                                        onclick="event.preventDefault();
                                                 document.getElementById('logout-form').submit();">
                                        Logout
                                    </a>

                                    <form id="logout-form" action="" method="POST" style="display: none;">
                                        
                                    </form>
                                </li>
                            </ul>
                        </li>
                    @endguest

via Chebli Mohamed