[SOLVED] Tango With Django - Fun With Forms URLconf Error

I am currently doing the latest tango with django course and have just about finished '8. Fun with Forms', I however cannot solve an error I am getting. The course tells us to make an add_page form and supplies us with the view and the form, all we really have to do is create the URL, I have done this however I cannot get it to recognize the URL for the add_page view.

Sorry I cannot post pictures as I do not have high enough reputation so I have given links.

This is the error I get https://i.sstatic.net/UrFxv.png

Here is my code

URLS -

from django.conf.urls import patterns, url
from rango import views

urlpatterns = patterns('',
    url(r'^$', views.index, name='index'),
    url(r'^about/', views.about, name="about"),
    url(r'^add_category/$', views.add_category, name='add_category'),
    url(r'^category/(?P<category_name_slug>[\w\-]+)/add_page/$', views.add_page, name='add_page'),
    url(r'^category/(?P<category_name_slug>[\w\-]+)/$', views.category, name='category'),

)

VIEWS -

from django.shortcuts import render
from django.http import HttpResponse
from rango.models import Category, Page
from rango.forms import CategoryForm, PageForm

def index(request):
    # Query the database for a list of ALL categories currently stored.
    # Order the categories by no. likes in descending order.
    # Retrieve the top 5 only - or all if less than 5.
    # Place the list in our context_dict dictionary which will be passed to the template engine.
    category_list = Category.objects.order_by('-likes')[:5]
    page_list = Page.objects.order_by('-views')[:5]
    context_dict = {'categories': category_list, 'pages': page_list}

    # Render the response and send it back!
    return render(request, 'rango/index.html', context_dict)

def about(request):
    message = "Rango says here is the about page. <a href='/rango/'>Index</a> "
    return HttpResponse(message)

def category(request, category_name_slug):

    # Create a context dictionary which we can pass to the template rendering engine.
    context_dict = {'category_name_slug': category_name_slug}

    try:
        # Can we find a category name slug with the given name?
        # If we can't, the .get() method raises a DoesNotExist exception.
        # So the .get() method returns one model instance or raises an exception.
        category = Category.objects.get(slug=category_name_slug)
        context_dict['category_name'] = category.name

        # Retrieve all of the associated pages.
        # Note that filter returns >= 1 model instance.
        pages = Page.objects.filter(category=category)

        # Adds our results list to the template context under name pages.
        context_dict['pages'] = pages
        # We also add the category object from the database to the context dictionary.
        # We'll use this in the template to verify that the category exists.
        context_dict['category'] = category
    except Category.DoesNotExist:
        # We get here if we didn't find the specified category.
        # Don't do anything - the template displays the "no category" message for us.
        pass

    # Go render the response and return it to the client.
    return render(request, 'rango/category.html', context_dict)

def add_category(request):
    # A HTTP POST?

    if request.method == 'POST':
        form = CategoryForm(request.POST)

        # Have we been provided with a valid form?
        if form.is_valid():
            # Save the new category to the database.
            form.save(commit=True)

            # Now call the index() view.
            # The user will be shown the homepage.
            return index(request)
        else:
            # The supplied form contained errors - just print them to the terminal.
            print form.errors
    else:
        # If the request was not a POST, display the form to enter details.
        form = CategoryForm()
    # Bad form (or form details), no form supplied...
    # Render the form with error messages (if any).
    return render(request, 'rango/add_category.html', {'form': form})

def add_page(request, category_name_slug):

    try:
        cat = Category.objects.get(slug=category_name_slug)
    except Category.DoesNotExist:
                cat = None

    if request.method == 'POST':
        form = PageForm(request.POST)
        if form.is_valid():
            if cat:
                page = form.save(commit=False)
                page.category = cat
                page.views = 0
                page.save()
                # probably better to use a redirect here.
                return category(request, category_name_slug)
        else:
            print form.errors
    else:
        form = PageForm()

    # made the change here
    context_dict = {'form': form, 'category': cat, 'category_name_slug': category_name_slug}

    return render(request, 'rango/add_page.html', context_dict)

FORMS -

from django import forms
from rango.models import Page, Category

class CategoryForm(forms.ModelForm):
    name = forms.CharField(max_length=128, help_text="Please enter the category name.")
    views = forms.IntegerField(widget=forms.HiddenInput(), initial=0)
    likes = forms.IntegerField(widget=forms.HiddenInput(), initial=0)
    slug = forms.CharField(widget=forms.HiddenInput(), required=False)

    # An inline class to provide additional information on the form.
    class Meta:
        # Provide an association between the ModelForm and a model
        model = Category
        fields = ('name',)


class PageForm(forms.ModelForm):
    title = forms.CharField(max_length=128, help_text="Please enter the title of the page.")
    url = forms.URLField(max_length=200, help_text="Please enter the URL of the page.")
    views = forms.IntegerField(widget=forms.HiddenInput(), initial=0)

    class Meta:
        # Provide an association between the ModelForm and a model
        model = Page

        # What fields do we want to include in our form?
        # This way we don't need every field in the model present.
        # Some fields may allow NULL values, so we may not want to include them...
        # Here, we are hiding the foreign key.
        # we can either exclude the category field from the form,
        exclude = ('category',)
        #or specify the fields to include (i.e. not include the category field)
        #fields = ('title', 'url', 'views')

    def clean(self):
        cleaned_data = self.cleaned_data
        url = cleaned_data.get('url')

        # If url is not empty and doesn't start with 'http://', prepend 'http://'.
        if url and not url.startswith('http://'):
            url = 'http://' + url
            cleaned_data['url'] = url

        return cleaned_data

I think that is all the code necessary however just let me know if there are another files you would like to see and I'll put them up. Any help appreciated, thanks