added a model in feedback for logging users who have already submitted feedback and made changes in corresponding views .
from django.conf.urls.defaults import *
from workshop.feedback import views as feed_views
urlpatterns = patterns('',
('^submit/(\w+)$', feed_views.submit_feedback),
('^list/(\w+)$', feed_views.list_feedbacks),
('^report/(\w+)$', feed_views.view_report),
)