comments = post.comments.filter(active=True)
    if request.method == 'POST':
        comment_form = CommentForm(data=request.POST)
        if comment_form.is_valid():
            new_comment = comment_form.save(commit=False)
            new_comment.post = post
            new_comment.save();
    else:
        comment_form = CommentForm()
    return render(request,
        'blog/post/detail.html',
        {'post': post, 'comments': comments, 'comment_form': comment_form})

{% if new_comment %}
        <p>You comment has bin add</p>
    {% else %}
        <h2>Add new comment</h2>
        <form action="." method="post">
        {{ comment_form.as_p }}
        {% csrf_token %}
        <p><input type="submit" value="Add comment"></p>
        </form>
    {% endif %}

if request.method == 'POST':

new_comment = comment_form.save(commit=False)

   def save(self, commit=True):
        """
        Save this form's self.instance object if commit=True. Otherwise, add
        a save_m2m() method to the form which can be called after the instance
        is saved manually at a later time. Return the model instance.
        """
        if self.errors:
            raise ValueError(
                "The %s could not be %s because the data didn't validate." % (
                    self.instance._meta.object_name,
                    'created' if self.instance._state.adding else 'changed',
                )
            )
        if commit:
            # If committing, save the instance and the m2m data immediately.
            self.instance.save()
            self._save_m2m()
        else:
            # If not committing, add a method to the form to allow deferred
            # saving of m2m data.
            self.save_m2m = self._save_m2m
        return self.instance