Leslie Mann and Elizabeth Banks go together in "Thinking"

Actress Elizabeth Banks and Leslie Mann have joined "What Was I Thinking?" It's a comedy project from Susanna Fogel and Joni Lefkowitz. Lynda Obst is producing. New Line has picked up the project.

The project is based on a book of the same name which saw Barbara Davilman and Liz Dubelman compile 58 bad boyfriend stories.

Elizabeth Banks and Leslie Mann will explore the comic side of bad relationships in the movie.

The story of the film is about a woman who gets dumped during her engagement party, causing her friends to spring into action and whisk her away on a ski trip for healing and hedonism.

Producer Lynda Obst said, "It's a story of how women help each other. And we do that by telling stories".

Leslie Mann, who began her career at the age of 17, would play the role of a woman who dates a lot but never seems to have serious relationships, while Banks is a woman on the rebound.

Two other lead female roles in the movie have yet to be cast.

Leslie Mann's upcoming film is "I Love You Phillip Morris", co-starring Jim Carrey and Ewan McGregor.

Mann has also appeared in the movies like "Funny People", "Shorts" and "17 Again".