Robert Redford gets sweaty.

And that's only the first reason why Barefoot in the Park is a great movie worth renting.

The 1967 big screen adaptation of comic genius Neil Simon's classic play of the same name is full of slapstick hilarity and smart writing, making for one of the best romantic comedies around. Oh yeah, it also stars a young and very attractive Robert Redford.

Redford plays Paul Bratter, a new lawyer recently married to Corie, portrayed by the equally attractive Jane Fonda. The original Dharma & Greg, Paul is conservative while Corie is a free spirit, but both are doing everything within reason to make this marriage last. He is always hard at work, and she is always ready for a little fun, so the squabbles are plentiful. The plot is a simple one as a pair of lovers, opposite in their thinking, try to survive in both their new New York City apartment and marriage.

Simon is the master of comedy and the play's original antics, love and laughs carry over to the screen. The couple's new apartment is a walk-up -- make that a five-floor walk-up -- so just imagine the fun Simon had in concocting stories around Redford continually climbing five flights of stairs as he settles into his new apartment. Redford not only gets sweatier with each trip, but he also gets even funnier.

In the role he created on Broadway, Redford is as charming and lovable as an uptight lawyer can be and Fonda shines as just the right quirky and energetic wife. The pair is adorable and at the prime of their acting careers.

Mildred Natwick is hysterically funny as Corie's mother and steals the movie with some of Simon's greatest written lines. She rightfully deserved the Oscar nomination she received that year for this role.

A variety of other supporting roles, from the telephone man to the elderly Bohemian living upstairs, played wonderfully by Charles Boyer, enhance the crazy mishaps of Paul and Corie.

Director Gene Saks, known for The Odd Couple, makes his big-screen directing debut with an understated style that helps balance the simple plot with the over-the-top gags. This technique also helps Barefoot in the Park retain its play-like style.

Do not be deterred by the age of the movie. Simple plots and no special effects are rare in current movies, even comedies, but Barefoot in the Park's jokes are timeless.