My view

def login(request):c = {}c.update(csrf(request))return render_to_response(request,
'login.html', c)def auth_view(request):username = request.POST.get
('username', '')password = request.POST.get
('password', '')user = auth.authenticate
(username = username, password =
password)if user is not None:auth.login(request,user)if request.method == 'POST':return HttpResponseRedirect('accounts/loggedin/')else:Retun HttpResponseRedirect('accounts/invalid/') 

Error occurs that function auth_view is returning nothing.

If the user is None, auth_view doesn't return anything. You must return an HttpResponse...