Success Message after Submitting a form

[Ahmed Khairy]

I have created this class with the success message but I am not receiving the success message I requested, other pages are showing them but this one is not 

What might be wrong? 

In the views: 

class PostCreateView(LoginRequiredMixin, CreateView):

    model = Post

    fields = ['caption', 'design']

    template_name = "post_form.html"

    success_url = '/score'

    success_message = "Your Design has been submitted for Review"

    def form_valid(self, form):

        form.instance.author = self.request.user

        return super().form_valid(form) 

in the HTML 

   <!-- Navbar -->

        {% if messages %}

            {% for message in messages %}

                <div class="alert alert-{{ message.tags }}" style="padding-top:80px">

                    {{ message }}

                </div>

            {% endfor %}

        {% endif  %}

Thank you 

[mohamed khaled]

just use SuccessMessageMixin

from django.contrib.messages.views import SuccessMessageMixin

class PostCreateView(LoginRequiredMixin,SuccessMessageMixin, CreateView):

    model = Post

    fields = ['caption', 'design']

    template_name = "post_form.html"

    success_url = '/score'

    success_message = "Your Design has been submitted for Review"

it will work 

[Ahmed Khairy]

Thank you Ramadan Kareem