Jurassic Park author Michael Crichton has been tied up and robbed at gunpoint.The two men searched through his California home but he wasn't harmed.Crichton, 59, is also responsible for creating the hit TV hospital drama series ER."An incident did occur, but everybody is fine, and that's all I can say because a kid is involved," said publicist Joseph Marich.Police said some items were taken from the Santa Monica house but the value was not immediately determined.Since his 1971 novel, The Andromeda Strain, was made into a film, Crichton has enjoyed a string of literary and Hollywood successes.More than a dozen...