"Taking Care of Business" is a formula comedy that essentially rides on the coattails of its two stars, James Belushi and Charles Grodin, both of whom trod familiar territory.

But, oh, what a couple of seasoned stars can do with a formula.

Belushi is a lovable car thief doing time in a genial California minimum-security prison where the inmates are so tame they throw him a farewell party as he approaches his release date.

In addition, Belushi plays a Chicago Cubs nut, and in this picture's fantasy world the Cubs are up against the California Angels in the World Series, with the last game coming up in Anaheim Stadium in a couple of days.

As fate would have it, Belushi wins a pair of tickets to the game by answering a radio trivia question, but, naturally, his release date is the day after the game.

So he concocts a plan with his prison buddies to escape so he can go to the game and return before his absence is discovered by the nasty warden (Hector Elizondo, the hotel manager in "Pretty Woman").

These scenes are intercut with uptight Chicago business executive Charles Grodin's ridiculously organized life, all of which is wrapped up in his Filofax — a datebook that contains his calendar, which plots his every move; an incredible array of credit cards; the key to his boss' Malibu mansion where he is going to stay during an important business trip, etc.

Grodin flies into Los Angeles and accidentally leaves his Filofax at a pay phone. Belushi, of course, finds it and sees inside that Grodin has offered a $1,000 reward for its return.

So Belushi heads up to the Malibu beach house to return it, but before he knows it he's mistaken for Grodin and finds himself simply going along with the assumptions of others. And why not? Grodin is very well-to-do and the beach house has every convenience you can imagine — and some you can't.

Meanwhile, Grodin, without any money or credit cards, finds himself on the skids — he's mugged, thrown into jail and has to endure an old high-school acquaintance (Anne DeSalvo) who thinks they've bumped into each other after 25 years as an act of romantic fate.

Mistaken-identity comedies are fairly common ground and despite a few inventive twists on the convention, the "Taking Care of Business" script, by Jill Mazursky & Jeffrey Abrams, doesn't vary much from the formula.

But Belushi and Grodin are such masters at playing these characters that they breathe life into the film at every turn. And director Arthur Hiller takes full advantage of his stars' talents.

Despite equal billing, Belushi gets the bulk of screen time over Grodin. He's hilarious, whether hustling someone with crass honesty or expressing disbelief at his good fortune. But Grodin also has his share of very funny moments; no one since Buster Keaton has mastered the deadpan stare so well.

There are some amusing bits of business from other cast members as well, chiefly DeSalvo, Mako as a Japanese businessman, Gates McFadden as an executive who's even more uptight than Grodin and the many actors who play Belushi's fellow prison inmates.

(Trivia buffs will want to note that two cast-members from TV's "Star Trek: The Next Generation" have prominent roles here — McFadden, "Star Trek's" doctor, and John de Lancie, who has the recurring "Star Trek" role of Q.)

"Taking Care of Business" is a bit raunchy in places and earns its R rating for sex, nudity and profanity, with some violence.