jsFiddle is a great tool for live preview, however there are lots of answers that goes along this :
Try this : http://jsfiddle.net/s0m3R4nd0mCh4r/
And nothing else is provided in the answer. Very often the code contained is fairly trivial and could be posted in the answer.
Should we edit those post to add the code in the answer? Should we simply ignore them? Is there any thing we could do to prevent people from adding answer like that?