Yes, President Barack Obama has seen the fabled book of secrets from the "National Treasure" film sequel. And he's staying zipped on what's in it. "I would tell you but I'd have to kill you," Obama joked in a White House interview with talk radio show host Michael Smerconish. Smerconish said his sons have seen "National Treasure: Book of Secrets," the Disney sequel to its 2004 hit, and know Obama has been provided the book of secrets that only Oval Office occupants are privy to. "I have," Obama said, going along with the radio host's reference to the fictional "book...