Cast members Cameron Diaz (R), Ashton Kutcher (C) and Lake Bell pose at the premiere of "What Happens in Vegas..." at the Mann Village Theatre in Westwood, California May 1, 2008. The movie opens in the U.S. on May 9.(Xinhua/Reuters

Cast member Lake Bell smiles at the premiere of "What Happens in Vegas..." at the Mann Village Theatre in Westwood, California May 1, 2008. The movie opens in the U.S. on May 9.

Cast member Cameron Diaz listens to co-star Ashton Kutcher (R) at the premiere of "What Happens in Vegas..." at the Mann Village Theatre in Westwood, California May 1, 2008.

Actress Eva Longoria Parker waves at the premiere of "What Happens in Vegas..." at the Mann Village theatre in Westwood, California May 1, 2008.

Cast members Cameron Diaz (L) and Ashton Kutcher pose at the premiere of "What Happens in Vegas..." at the Mann Village theatre in Westwood, California May 1, 2008.

Cast member Cameron Diaz laughs at co-star Ashton Kutcher (R) at the premiere of "What Happens in Vegas..." at the Mann Village theatre in Westwood, California May 1, 2008.