How real is the da vinci code?

Im sorry to be boring and re-hashing the most over exposed news this summer, but Im gonna...the da vinci code, how real is dan browns theory? or is it just that, a theory? and if its true, is it so bad that jesus had a child? does it take away any of his message or good work? please dont all scream heathen at me all at once, or call me stupid,its just a question.