Jason Segel has written a series of young adult novels.

The 'How I Met Your Mother' actor has penned three books based on a script he sold when he was 21, which he managed to buy back when he became famous.

According to VH1, Jason said he ''sold the script for super cheap because I didn't know any better back then.

''As I got more successful I kept hoping they wouldn't know I was the same Jason Segel as the Jason Segel they bought the script from.''

While Jason, 33, wouldn't give away too many details on the book series, he did say: ''It's about kids facing their biggest fears, that's about all I can tell you.''

In February Michelle Williams, 32, dumped Jason over concerns about their long distance relationship.

A source said: ''She cares a great deal for Jason but is not ready to make a commitment. Maybe if they were together day-to-day, she would have more confidence in a future. But not at this time.''

Jason is based in Los Angeles for his TV show while Michelle lives in New York with her seven-year-old daughter Matilda and the commute eventually became too much for the pair.

A second source added: ''Jason never got rid of his place in LA, and Michelle's life with Matilda was and has always been in New York. While Jason made every effort to make them a priority in his life - and they were top priority - he still couldn't drop everything and leave his life and career in LA.''