This Vegas is an absolute sure bet for big laughs. A classic comic battle of the sexes romantic comedies have been doing successfully for years from Tracy and Hepburn to Hudson and Day--and now Diaz and Kutcher. Jack Fuller (Kutcher) is a slacker carpenter just fired by his ungrateful father (Treat Williams). Joy McNally (Diaz) is a commodities trader who lives her life by the numbers--both professionally and personally--and has just been dumped by her fiancée (Jason Sudeikis). At the urging of their respective best friends Hater (Rob Corddry) and Tipper (Lake Bell) they head to Vegas for the weekend designed to help them forget their big city woes. As in all films of this ilk Jack and Joy “meet cute” when both sets of friends are accidentally booked into the same hotel room. Once that mess is sorted out they all set off on a wild drunken party spree which ends with a blitzed Jack and Joy’s nuptials at a quickie wedding chapel. As reality strikes along with the light of morning the now-battling couple plan an annulment which becomes complicated when Jack hits a $3 million dollar slot jackpot with Joy’s quarter. Both claim the cash but in order to get the money a New York judge (Dennis Miller) determines they must prove they are serious about the marriage and gives them six months to become a real couple. As with all the legions of “opposites attract” comedies Hollywood has dished out over the years these confections live or die on the chemistry of the star--luckily for What Happens In Vegas Diaz and Kutcher are well matched in every way. Of course Diaz is no stranger to ‘party girl’ scenarios so the early scenes fit her like a glove. Kutcher counters her nicely as a slacker dude caught up in circumstances beyond his control. An early sequence in which they check into the same room is played at such high-pitched hysteria--followed by a Vegas spree that seems so MTV-quick cut style-- you worry the film will not come back down to earth. But thanks to its stars and a generally fine supporting cast the rest of the picture recovers in style and is played for laughs grounded in reality. Although this is essentially a Cameron/Ashton showcase there are still some great wisecracks from the actors cast as their friends particularly Bell (Over Her Dead Body) who aces her timing and delivery. Corddry also scores as Jack’s loser friend and novice lawyer. In another era it’s the type of role Tony Randall would have played and Corddry is inspired casting here. Comedian Miller is cast against type as the judge and Williams has little do as Dad. For some reason Queen Latifah with no billing except on the end credits accepted a bland role as a marriage counselor Jack and Joy are forced to see. With his little-seen gem last year Starter for Ten starring James McAvoy newcomer Tom Vaughan showed considerable skill directing character comedy. His first big studio outing is much broader but again confirms his talent for getting the best out of his stars. Vegas isn’t loaded with style or signature shots but it keeps us engaged for 98 minutes and sports a light tone that lets the audience have as much fun as the actors seem to be having. Early scenes in Las Vegas (only about 15 minutes of the entire film actually “happens” there the rest in New York) are a bit too frenetic for their own good but thankfully Vaughan gains his stride and the laughs come more smoothly once the story heads back to New York. The screenplay by Dana Fox smartly centers her clever story (with its inevitable conclusion) around the gradual attraction of the two leads who prove what happens in Vegas is only the beginning of the real fun.