NoReverseMatch: u'notification' is not a registered namespace 这个应该怎么解决
urls.py：
# -*- coding: utf-8 -*
from django.conf.urls.defaults import *
from django.contrib.auth.decorators import permission_required
from django.views.generic import TemplateView
from .views import WriteMailView
urlpatterns = patterns('',
url(r'^writemail/$', WriteMailView.as_view(), name='write_mail'),
)