Ajax call with class-based view

[valerio orfano]

I have the following template:

<script>
    $(document).ready(function(){
   
        function captcha() {
            $.ajax({
                type: "POST", 
                url: "../captcha",
                data:{},
                contentType: "application/json",
                dataType: "json",
                success: function(data) {
                    alert(data);
                  },
                failure: function(data) {
                        alert(data);
                     }
                });
           
        }
       
        $(".btn_success").click(captcha);       
    });
    </script>


<form action="./captcha" method="POST">{% csrf_token %}
    <div style="color:red">{{ form.non_field_errors }}</div>
    {% for field in form.visible_fields %}
        {% if field.name = 'captcha' %}
            {{field}}
            <input type='submit' id="btn_success" class="btn_success" value = "Invio"/>
        {% endif %}
        <span>{{ field.errors }}</span>
    {% endfor %}
</form>


views.py:

class CaptchaView(CreateView):
    template_name = "captcha.html"
    form_class = MyForm
   
    def form_invalid(self, form):
        if self.request.is_ajax():
            to_json_response = dict()
            to_json_response['status'] = 0
            to_json_response['form_errors'] = form.errors

            to_json_response['new_cptch_key'] = CaptchaStore.generate_key()
            to_json_response['new_cptch_image'] = captcha_image_url(to_json_response['new_cptch_key'])

            return HttpResponse(json.dumps(to_json_response), content_type='application/json')
        else:
            return HttpResponse("test1", content_type='application/json')

    def form_valid(self, form):
        if self.request.is_ajax():
            to_json_response = dict()
            to_json_response['status'] = 1

            to_json_response['new_cptch_key'] = CaptchaStore.generate_key()
            to_json_response['new_cptch_image'] = captcha_image_url(to_json_response['new_cptch_key'])

            return HttpResponse(json.dumps(to_json_response), content_type='application/json')
        else:
            return HttpResponse("test2", content_type='application/json')


and forms.py
class MyForm(forms.ModelForm):
    sections = forms.ChoiceField(choices=get_sections())
    classes = forms.ChoiceField(choices=get_classes())
    subclasses = forms.ChoiceField(choices=get_subclasses())
    groups = forms.ChoiceField(choices=get_groups())
    subgroups = forms.ChoiceField(choices=get_subgroups())
    captcha = CaptchaField()          
    class Meta:
        model = MyModel
        exclude = []
      
and ursl.py
url(r'^captcha$', views.CaptchaView.as_view(), name="captcha"),


but the CaptchaView is invoked but not as ajax call. What am i doing wrong??

Thanx in advance

valerio