WARNING: ON THE ERR

Radioland Murders is the kind of dippy, overheated show-biz fantasy that besmirches the good name of slapstick. It doesn't do much for the long-cherished romance of radio, either.

The operative cliche here--and it operates overtime--is the oldest one of all: The show must go on. The time is 1939. The place is a mythical Chicago radio station called WBN, which is trying to make its national debut when we stumble in on the chaos. While everyone talks very fast (everyone in the Thirties talked fast, these moviemakers seem to think), we are subjected to a frantic stream of swing bands and old vaudevillians, talking pigs, swaying blond chorines, roller-skating penguins and radio tough guys, all decked out in costume, all grabbing their chunks of air time, all meant to recall the golden age of a medium now dominated by talk-show know-it-alls and empty-headed DJs.

Meanwhile, there's also a murderer at large in the studio. And an employee marriage in trouble. And a sound-effects man who can't find the right kind of melon to simulate the sound of a guy getting bopped on the head. And a group of harried writers rushing scraps of mangled dialogue to actors just seconds before they go on the air.

Star Wars mogul George Lucas is the executive producer of this disaster, and things might have turned out better if he'd directed it himself. As it is, Mel Smith (The Tall Guy) puts such frenzied pressure on himself and the huge cast and two dozen tangled plot lines that the movie smashes itself to pieces from sheer centrifugal force.

While we spin, there's barely time to notice Mary Stuart Masterson as WBN's savvy Jane-of-all-trades, Brian Benben's confused chief writer, Ned Beatty's blustering station owner or Scott Michael Campbell's Billy, a page stuck in the middle of every crisis. Michael Lerner sails by as a tough Chicago cop chomping a cigar, and we get fleeting glimpses of Jeffrey Tambor as an incompetent floor director, Corbin Bernsen as a vain announcer and Anita Morris as the station's resident vamp.

In all, there were five writers on Radioland Murders, including Lucas and the American Graffiti team of Willard Huyck and Gloria Katz. None of them have delivered a script any more coherent than what the typewriting wretches at WBN are cranking out two minutes before air time. The movie means to be swift, sure. But does it mean to be haphazard?

Who's the WBN killer? Who cares? While this mess careens along, you're too busy figuring out what's worse--the movie's forced screwball style or its processed nostalgia. I haven't been so relieved to hit the lobby since Kevin Costner pretended he was Wyatt Earp.