Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: Thanks for the great article Courtney! http://tennis.si.com/2013/05/09/bethanie-mattek-sands-wta-tour/  Responser: Please let me set up a fans forum in London during WImbledon for you .. are you working on 5 live again ?
