Josh Hartnett's character, Matt, in Michael Lehmann's "40 Days and 40 Nights," denies himself what he wants most. Sex. For forty days and forty nights. No women, no self-gratification. You'd hardly call sex an addiction since every healthy person feels the need (even from the age of two, as Freud suggest), but it's hardly as strong a passion as the urge to see movies. Nonetheless for Matt and his disbelieving friends, he takes the vow of celibacy. So skeptical, in fact, are his pals, that they take bets to whether he can pull it off, er, not pull it off, and when the kitty builds to $18,000 the guys who wager that he won't succeed make sure he's keeping his side of the bargain. His roommate even has a special light that he uses to scan Matt's sheets to see that, as he puts it, "no fluids are liberated."

You wouldn't think a one-joke comedy can pull it off (so to speak) for ninety-two minutes but thanks to a snappy script by Rob Perez, swift pacing by director Michael Lehmann, and perhaps most of all the clean-cut good looks and affable personality of Josh Hartnett, "40 Days" succeeds in keeping the audience charmed, smiling, and happy. What's particularly admirable is that despite its "R" rating, this Miramax release shows how a subject that could easily become the vulgar pic du jour in a genre that stretches from "There's Something About Marry" to "Van Wilder," need not be off-the wall ham-fisted and tasteless but can intelligently treat a subject that has kept audiences in stitches since the days of Aristophanes. What we have here is a group of kids in their early twenties who can utter complete sentences without a "like" or "totally" or "y'know" throughout.

What motivates the action, or inaction, of the central character is that Matt has just been dumped by his girlfriend, Nicole (Vinessa Shaw) and tries to get her out of his mind by shacking up with a bevy of gorgeous women. The trouble is that each relationship reaches an impasse when Matt, at a moment that he should be happiest, imagines that the ceiling is cracking. He believes that his problem is his fixation on sex with Nicole (who is now engaged to another guy) and that he can recover his sanity by freeing himself from desire. Thus his vow to have not a single sexual relationship, not even with himself, for 40 days (the period of time that Jesus went into the desert to test his ability to deflect Satan's temptations).

If working for a dot-com company is anything like the way it's portrayed in this fun film, how disastrous that so many of these organizations went belly-up during the past couple of years. Matt is surrounded by fun guys, seductive women, and best of all he "clicks" with the lovely girl-next-door type, Erica (Shannyn Sossamon). True to the conventions of romantic comedy, director Lehmann and scripter Rob Perez make sure to put obstacles in their way to keep them apart as long as they can until their inevitable reconciliation. Along the way, we're treated to some solid comic interaction by an ensemble of young people who look as though they're enjoying themselves as much as we are.