Screenwriter Richard LaGravenese is to direct the movie adaptation of Irish author Cecelia Ahern's best-selling book 'PS, I Love You'.

The Hollywood Reporter says that the book tells the story of a young widow whose late husband has left her a list of 10 messages, which are intended to help her with the upheaval in her life.

LaGravenese's other credits include the screenplays for 'The Horse Whisperer' and 'The Bridges of Madison County'.

He also wrote 'The Fisher King' and is currently working on the screenplay for 'The Secret Life of Walter Mitty'.