David Nicholls: How do you follow up a publishing sensation?

It's every writer's dream - a bestselling novel that sells millions of copies all over the world and is turned into a Hollywood blockbuster.

David Nicholl's One Day became a publishing sensation, but how do you follow something which has been such a success?

Five years on, the author's back with a new novel, which he says is even better. David popped in to tell BBC Breakfast about it.