## The View

def index(request):
	username = request.POST['username']
	password = request.POST['password']
	user = authenticate(username=username, password=password)
	if user is not None:
		if user.is_active:
			login(request, user)
			return HttpResponseRedirect('/home/')
		else:
			return HttpResponseRedirect('/disabled/')
	else:
		return HttpResponseRedirect('/invalid/')

## The Error
MultiValueDictKeyError at /
"Key 'username' not found in <QueryDict: {}>"