Error MultiValueDictKeyError: 'rating' is resolved.

**Error Reference:**

Traceback (most recent call last):

  File "/home/glab/gstudio_metastudio/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 112, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)

  File "./gnowsys_ndf/ndf/views/ratings.py", line 24, in ratings
    rating=request.POST['rating']

  File "/home/glab/gstudio_metastudio/local/lib/python2.7/site-packages/django/utils/datastructures.py", line 301, in __getitem__
    raise MultiValueDictKeyError(repr(key))

MultiValueDictKeyError: "'rating'"