When you watch a movie titled What Happens In Vegas, you pretty much know what to expect.

There will be debauchery. There will be drunkenness. There could also be an unwanted marriage.

And THAT was specifically the case in the new Cameron Diaz, Ashton Kutcher romantic comedy. Diaz plays Joy McNally, a successful executive who has just been dumped by her fiance (Mason), played by Jason Sudeikis, in the most awkward of ways.

At a party. His party. A surprise party.

Mason walks in and tells an unsuspecting McNally that while he appreciates her willingness to experiment sexually, he can't take the fact that she's always "on."

In typical Diaz fashion, she is always on.

However, to her credit, this is one aspect of her personality that, I think, people like. When her perky, fun, good-time personality shines through in a role suited to how she really is, it works.

That started with "There's Something About Mary," and I think I had seen it most recently (before this) in "The Holiday," a movie I liked quite a bit.

But to turn it "off," she and a girlfriend (Lake Bell) head to Vegas. While there, McNally meets up with Jack Fuller (Ashton Kutcher), who has just been fired from his job by his father (Treat Williams).

A drunken night of fun later, and they're hitched.

Both McNally and Fuller realize their mistake by morning, and after some plop-plop, fizz-fizz, oh-what-a-relief-it-is, they decide to try to end the marriage.

However, Fuller plops a quarter he bummed from McNally into a slot machine and wins $3 million. Immediately, McNally realizes she has to hang on to this marriage for the sole purpose of being able to claim a piece of the money.

So, Diaz and Kutcher's characters end up in court, a proceeding presided over by Dennis Miller, who in turn orders the couple to try to work it out. The premise that a judge would order counseling to a couple who got married on the basis of knowing each other for a couple hours is ludicrous.

But there was big money involved, so I guess the only way to determine how the winnings should be divided is to see who is or was most committed to the sham of a marriage in the first place. And McNally and Fuller do this with the help of Queen Latifah.

Long story short, a romance develops along the way, slowly but surely, with all the typical devices romantic comedies invoke, such as some tension at the end with the male lead messing up and trying one last time to get his girl back.

All of the basics are here, and while none of "What Happens In Vegas" was remarkable, it was fun. That's what you expect out of Diaz and, to a certain extent, Kutcher.

And that's what one would probably expect out of Vegas.

Note: If there was a standout performance in the movie though, it was from Rob Corddry, who plays both Kutcher's Vegas buddy and his divorce lawyer. Most of you know Corddry from his time on The Daily Show, so you're probably not surprised how good he was in this.