By Emily Dugan One of radio's funniest shows is to return, but who can possibly replace the late Humphrey Lyttelton? The search is on, but the field is wide open, as Emily Dugan reports Just as the nation had become resigned to the idea that the nonsensical radio quiz show I'm Sorry I Haven't a Clue would never again be heard on the airwaves, hope of a return for the popular series is on the horizon.