THIS IS JUNK, and not even the good junk that we've come to expect from Neil Simon. Many of the touches in the movie are familiar--you will probably recognize your own refrigerator--and once an hour one of Simon's characters delivers a comic yet profound line about American relationships on the run in the 1970s. But Chapter Two, an adaptation of Simon's long-running Broadway play, never grasps onto more than the obvious.

Even though much of the movie's plot is based on serious events in the author's own life, it still lacks the credibility in its comedy that Simon usually pulls off. For starters, the two main characters, George Schneider and Jennie McClaine (James Caan and Marsha Mason), take more cabs than anybody else in the entire city of New York. They're always hopping into taxis at the beginning of scenes. For a successful writer like George, this is less surprising than for a little known actress. Where does she get the money to lead such a life?

What's even more troublesome is the way director Robert Moore chooses to transform Simon's play into film. It's obvious Chapter Two was a play first, because virtually all of the heavy dialogue takes place in one room. The camera moves aimlessly from corner to corner, without knowing where to focus after a while. And when Caan and Mason aren't thrashing out all of the problems in their stalemate of a marriage, there's no action to speak of, only snapshots of the honeymoon couple in Bermuds.

The biggest trauma of the movie is trying to decide if you dislike James. Caan more for rushing into a marriage he wasn't mentally prepared for, or Neil Simon, whom you wish had never dramatized these recent events from his life. The plot, no matter how true, still produces one of Simon's most uninteresting relationships. And we've come to expect quite a bit from the creator of Oscar and Felix, and, more recently, the wonderful role of Elliot Garfield in The Goodbye Girl.

George Schneider, on the other hand, spends most of his time pining over his recently deceased wife, and after a while, it's clear that there is not much depth to his character, or to the story. Schneider is a novelist, the kind who writes 300 pages of a book without knowing where it's going, only partially because he's distracted by the loss of his wife. His brother Leo (impressively played by Joe Bologna) fixes him up with many women as he steps out into the world again, including a ghastly disco queen named Bambi. For George Schneider, chapter two in his life needs drastic revision unitl he catches up with Jennie McClaine, Little known New York actress. Convincing her that "nothing is inevitable because dates are man-made," he wines and dines her into a marriage after only two weeks, much to the surprise of Leo, and Jennie's confidante Faye (Valerie Harper). But their "fortune cookie romance" comes to an end very quickly after their honeymoon in Bermuda, where George had also taken his first wife. Back in New York, George only takes time out from gazing at pictures of his deceased spouse in his brownstone to wind up and deliver many caustic pitches to poor Jennie, who can't find the way to cope with his moodiness.

IT'S ALL fairely silly, and the tension doesn't hold up when juxtaposed to Richard Dreyfuss leaving Mason for the West Coast in The Goodbye Girl. Then we really cared, but now we wish Simon hadn't worn his sould on his sleeve for all the world to see. Caan's portrayal of George, as well as Simon's impotent screenplay, causes our discontent. We're used to Caan as a macho character, but here he plays a writer "not gorgeous, but sweet-looking, with an intelligent face" (how he's described to Jennie) and he just can't pull it off. He doesn't know how to ask his wife to get him a chili dog with that sparkle of intimacy.

Marsha Mason provides a foil for Caan in much the same spirit as she did for Dreyfuss--whiny, forceful when need be, a bit overwhelmed--and we accept her much more willingly. She understands her role and little wonder--in real life she's Mrs. Neil Simon. She does have a definite advantage over Caan in that respect.

Bologna and Harper carry on the affair that we expect them to have with searing honesty and much acting skill. It is the one believable exchange in a movie whose humor usually shortchanges its central characters. Simon must be admired for daring to share so openly with the public, but he's gone past the line of accessibility. He's inviting us into the bedroom of his mind, and it's an uncalled for invasion of privacy.