The first full-length trailer for Daniel Radcliffe's new movie What If has been released, check it out here.

The Michael Dowse-directed film sees Radcliffe's character fall in love with a woman, played by Zoe Kazan, who already has a boyfriend.

Girls star Adam Driver offers some comic relief in the form of Radcliffe's best friend and Rafe Spall, Megan Park and Jemima Rooper also star.