The Knack is a perfect summertime film, a celluloid gin and tonic -- bright, sparkling, mildly intoxicating, and not-at-all a serious people's film (although it may break up the stodgy old bag downstairs).

Its greatest charm is big-eyed Rita Tushingham, fresh from A Taste of Honey and Girl With Green Eyes, but here much more the comedienne. She plays Nancy, an open mouthed arrival in London who asks everyone for directions to the YMCA. She ends up instead with three bachelors.

Tolen has The Knack. With a tap on his snare drum, a fillip of his hair, or an rpm of his white cycle he can banish the serneity of any normal giri and transform her into a quivering mass of ungovernable desire. Colin wants to get The knack. He's just a mild-mannered, horny school-teacher who'd be satisfied with one of Tolen's girls. So when Nancy arrives, Colin decides to make his feeble play, with some help from Tom, a crazy Irishman who must paint everything white. Good destroys evil, Colin gets Nancy, and Tolen loses The Knack.

Director Richard Lester apparently saw he had a good thing going in A Hard Day's Night, so he repeats his rapid-cut technique here with equal success. He had a stage hit on his hands before he began filming, for The Knack, filled theatres in London -- where Miss Tushingham created the role Nancy -- and New York. But Lester made an indoor play into an outdoor movie, spicing it with wild cycle rides, water skiing romps, and traffic tie-ups. His sight gags are old hat slapstick but none the worse for wear, and they don't overshadow the personal humor but become a part of it.

Hay Brooks is an oily-smooth sinister Tolen in narrow trousers, high-heeled boots and dark glasses, cool, suave, and detestable. Michael Crawford and Donal Donnelly play awkward Colin and buck-toothed Tom with childish glee and exuberance, especially when Colin finds a bed far bigger than Tolen's could possibly be.

The Knack moves too fast to let you or the actors take it seriously. After you've gulped down the last frame, and you've stopped warmly tottering out of the theatre, you're sure of just two things: you're seen a very funny movie, and Rita Tushingham is the greatest girl ever made.