Returns random joke every time this webservice is invoked.

The following operations are supported. For a formal definition, please review the Service Description.

• getJoke
  Joke categories:
  
  Murphy's Laws - 7
  Q&A - 3
  Unnatural Laws - 18
  Cool Jokes - 6
  Blondes - 2
  Random(contains Adult) - 1
  Lawyers - 5
  Headlines - 8
  Military - 9
  Accidents - 4
  Excuses - 10
  Answering machine - 11
  All categories - 0