A worrisome title, "Hardly Working," heralds a slapstick farce of almost painful decrepitude. "Hardly Moving" would be closer to the mark. Now at area theaters, this depressing comeback vehicle for Jerry Lewis develops irreversible inert tendencies right after the prologue, a sprightly montage of sight gags from his vintage comedies.

When the uninspired new material commences, Lewis is briefly disguised in the baggy pants and greasepaint of a circus clown. He goes through the motions of placing a suitcase on a table, opening it and extracting the contents -- an outrageous multitude of objects ending with a dwarf clown.

Although Lewis contributes nothing remarkable to this venerable act -- no particular finesse and no funny reactions -- a group of colleagues is shown hilariously overreacting. You'd think these professional clowns had never seen the show before.

Meanwhile, a middle-aged woman in the audience also beams with excessive delight. This is Susan Oliver, once a favorite leading lady for Lewis and now recruited to play his doting sis. It's an indication of the aging star's failing judgment that he needs these approving props.

When a performer's creative energy and critical perspective flicker out, he becomes susceptible to the pitfalls of vanity production. "Hardly Working" rapidly degenerates into a textbook of example of this lamentable phenomenon.

Lewis solicits favorable reactions before justifying them by the quality of the work at hand, first by evoking memories of his best work and then by calling attention to supporting players acting deferential to his own character. At the same time, he invites disillusion by reminding us of the younger, nimbler comic self he can no longer duplicate.

The next gambit is gratuitous pathos. After the performance the circus proprietor (very badly directed by director Lewis) announces that the show has gone bust. You can imagine why, but this mawkish interlude is merely a setup for the mawkish aftermath, which finds Lewis gazing mournfully into his makeup mirror. He applies a smear of cold cream and then pauses to shed a little tear before the scene fades.

After removing the sorrowful greasepaint, Lewis is meant to revert to the madcap form that once endeared him to a generation or two of American juveniles, myself included. The out-or-work clown, Bo Hooper, is steered into a succession of jobs and makes a slapstick shambles of them: gas station attendant, bartender, Japanese chef, disco deejay, store clerk, postal clerk.

In his prime Lewis could usually construct a whole feature around the chaos his character created trying to master a single occupation: draftee, rookie cop, errand boy, bellhop, domestic, hospital orderly, academician. In "Hardly Working" he keeps breaking down after each situation is exploited for a clumsy gag or two underlining Bo's headlessness.

The arbitrary nature of the slapstick is underlined when Bo goes from incompetence to expertise overnight in his postal job. Flimsy as it is, the plot is also a tangle of coincidental elements, with Bo unaware that the doll-faced Pepsodent blond (Deanna Lund), who's taken an inexplicable fancy to him, is also the daughter of his fuming superior (Harold J. Stone), who's also in the dark about his aging baby girl's taste in patsies.

The sight gags provoke scattered mirth, and every so often there's a bit that's arguably worth the effort: a surreal cartoon payoff where Lewis shows a curio shop customer an ornamental porthole, and they're hit by waves as soon as he pries the glass open; the peeved reaction of a corpulent diner (a well-played bit by Peggy Mondo), who advises Lewis, with wittily exaggerated articulation, to "Go away from me . . . Gooo . . . Gooooooo" after he gets tangled up in her shawl and insists on apologizing profusely. But nothing is as deft as the bits recalled in the prologue including a house-cleaning sequence in which Lewis repeatedly bumps antiques off their pedestals and then catches them an instant before disaster.

But the most telling indication of Lewis' decline is a disco dream sequence in which he flirts with a spoof of "Saturday Night Fever." At one time Lewis would have been sensational kidding John Travolta's dance numbers. His crazy-legged virtuosity as a comic hoofer and his manic exuberance as a personality would have been ideal tools for a sendup of disco choreography. Now you're so conscious of his age and slowness that the impersonation turns into an embarassment. Lewis looks like some pathetic old sport who doesn't know how to act his age.

Lewis in his prime was a graceful, streamlined comic energy source, a Jewish dervish, and it wasn't until the late '60s, after almost 40 movies, that he finally ran out of spontaneity.

"Hardly Working" picks up where his fading vehicles left off. Moreover, it picks up a less attractive comic. When Bo removes his greasepaint, it's distressing to see Jerry Lewis' thickened features. The puffy checks and droopy jowls are inappropriate for the excitable juvenile's range of expressions that Lewis once made distinctive.

Lewis appears to have been oblivious to a number of such details that an objective director might notice immediately. That's vanity moviemaking for you. Instead of holding a mirror up to nature, the filmmaker can't see beyond his own dim reflection.