Ever wonder where scripts go when they're rejected by Jim Carrey?

They go to Jim Carrey wannabes.

In this case it's Harland Williams, who proudly lists among his credits a role in "Dumb & Dumber" . . . though I can't recall him . . . and you couldn't pay me enough to watch that movie again.

But I digress.

Williams' first starring role is in the occasionally amusing, decidedly silly and sometimes irritating "RocketMan." And Williams would probably be pleased as punch to admit that he is the film's main source of irritation.

In what amounts to little more than a reworking of "The Reluctant Astronaut" (Don Knotts' first starring film some 30 years ago), Williams plays a computer geek who has programmed some of NASA's software for the first manned flight to Mars.

When the flight crew's computer specialist is disabled — by Williams' bungling hijinks — Williams finds himself recruited and rushed through astronaut training.

But he proves to be such an idiot that the flight crew — and most of the ground crew — are driven to distraction.

As is the audience.

After Williams is pushed through the required tests, he joins a chimp and astronauts Jessica Lundy (who eventually falls for Williams!) and William Sadler (who hates him) to travel to Mars. Naturally, idiocy ensues.

There are several wasted talents here, chiefly (unbilled) Shelly Duvall, as Williams' flighty mother, and Beau Bridges, as a former astronaut who believes in Williams.

But this film is really just a showcase for Williams' manic abilities, and a little of him goes a long way. Of course, that's also true of Carrey. (And, 30 years ago, Jerry Lewis.) For me, Williams' childish antics wore out their welcome in the first 15 minutes. (His tag line is "It wasn't me," repeated about a million times.)

Young children — very young children . . . infants . . . fetuses, perhaps — may enjoy this, but their parents should beware.

And though the film is rated PG and contains no profanity . . . in itself a remarkable accomplishment these days . . . there are a few vulgar gags, as when someone slips on vomit, and an extended gag about fatulence in a space suit. There is nothing approaching the level of Carrey achieves in his films, however.

It might also be of interest to note that some of the Mars scenes were shot in Moab, using a red filter. The Moab Film Commission gets a credit at the end. (There is also a quick joke following the end credits. It's not worth the wait.)