Meet Charlie Baileygates (Carrey), a veteran of "the greatest law enforcement organisation in the land" (the Rhode Island police force).

Charlie is mild-mannered, hard working, always helpful, and a devoted, loving father to three sons.

Unfortunately, Charlie has Split Personality Disorder, and when he runs out of his medication...

Meet Hank Evans (Carrey), Charlie's ultra-aggressive alter ego. Hank has a dirty mouth, he drinks like a fish and has some filthy habits.

Charlie and Hank have nothing in common...with the exception of Irene Waters (Zellweger), a beautiful woman with whom they've both fallen in love.

With his job at risk, he's assigned to escort traffic violator Irene to the police in New York State.

On the road trip, he has to battle corrupt cops as well as trying to keep his alter-ego under control.

The Farrelly brothers extend the string of heartfelt, stomach-turning comedies that began with Kingpin and continued with Dumb and Dumber and the gross-out masterpiece, There's Something About Mary.

Though not on the level, in terms of amiability, of their blockbuster There's Something About Mary, this crass comedy should do the job for young adults, especially males.

The Farrellys pack in no shortage of their trademark gross-out gags, but the film also includes a sort of dopey, boyish sincerity and a good-natured sympathy for the underdog that may prove capable of winning over even the most sour of souls.

Although Carrey is brilliant as a schizophrenic (the formula that's expected to draw the most laughs), the idea that works the best is that of Charlie's African-American triplet sons (you'll have to see the movie to understand).

Played by Anthony Anderson, Mongo Brownlee, and Jerod Mixon, their profanity-laden dialect teeters on stereotype, but what isn't so cliche is how super-intelligent these three are.

Needless to say, their brainy, swearword-smothered speeches make for an hilarious and ironic juxtaposition.

Dominic Bloch