Possible error in vote function

[mr_rjharris@…]

def vote(request, poll_id):
    p = get_object_or_404(Poll, pk=poll_id)
    try:
        selected_choice = p.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the poll voting form.

I tried to generate an exception by opening a blank page in the browser and entering an url such as

http://localhost:8000/polls/1/vote/

and received the following response

NameError at /polls/1/vote/

global name 'Choice' is not defined.  etc.

I modified the except line to

except KeyError:

and the code worked as expected, opening the url http://localhost:8000/polls/1/vote/

[mr_rjharris@…]

BTW, this pertains to ​https://docs.djangoproject.com/en/1.4/intro/tutorial04/

[anonymous]

Sorry, I just failed to add Choice to the list of polls.models