Is "The Man With Two Brains" smarter than the average jerk? Steve Martin tests his funny-guy I.Q. and finds that he's right two out of three jokes in this ultra-silly, slapstick, slapdash, shamelessly crass and tacky take-off of "Frankenstein's Daughter" marries "Dr. Kildare" who falls in love with "Donovan's Brain" and honeymoons in Vienna. It's cute.

Kathleen "Body Heat" Turner, chunkier than the time she tested Bill Hurt's thermostat, nonetheless steams the stethoscope of Martin's Dr. Hfuhruhurr, egocentric inventor of screw-top brain surgery. Hfuhruhurr (the sound of one dog coughing) nearly kills beautiful Delores Benedict (Turner) in a car accident, but performs screwball surgery in time to save her life. Delores is the "scum queen": She thinks Fredericks of Hollywood when she thinks designer. But Hfuhruhurr, blinded by her lingerie, doesn't comprehend her treachery until after he's married her. She uses her recent brain job as an excuse for "not tonight, dear" headaches that keep Hfuhruhurr in a constant state of ardent agitation.

Hoping to consummate their marriage, the doctor takes his bride for a working honeymoon in Vienna, where he meets the mad Dr. Necessitor (David Warner) who has learned to perform brain transference via a converted video-game machine that still takes tokens.

In Necessitor's drafty castle-in-a-condo, Hfuhruhurr notes, "The only time we doctors should accept death is when it's a result of our own incompetence." Whereupon he falls in love with Alice Uhulumahamey by mental telepathy. Alice is Cookie Jar No. 21 in Necessitor's collection of brains awaiting body donors.

Having fallen into the classic love triangle, Hfuhruhurr tries to resolve it by moving into Alice's jar, but Alice can't live here anymore, says Necessitor. She'll die without a donor body, preferably one killed with Pane in the Glass window cleaner, the method preferred by Vienna's mysterious elevator killer.

It's a wacko scenario -- written by the team of Martin, Carl Reiner and George Gipe -- to accommodate Martin's stand-up style. He's the only comic who'd think of performing double-brain surgery in a pair of bunny ears. But Reiner, who also directed the film, seems to be still rooted in Mel Brooksian sensibilities, flailing at times in the pursuit of comedic anarchy.

If laughter is the best medicine, then take "The Man with Two Brains" and call the doctor in the morning. THE MAN WITH TWO BRAINS -- At area theaters.