As an introduction to Alex Kovac, a chatterbox malarkey artist from the Borough of Queens, the first 10 minutes of "Lookin' to Get Out" seem quite promising.

Jon Voight, the characteristic tension gone from his face, wisecracks his way through a high-stakes poker game, laughs off the new graffiti on his white Rolls-Royce and then goes home to tell his morose but loyal pal Jerry Feldman, played by Burt Young, that they're deeper in dept than ever.

As two heavyset loan sharks close in for the kill, Alex, Jerry and the whole movie pack off to Las Vegas for the big score that will set everything straight. If this seems to signal a standard caper story to come, well -- Young has quickly shown himself an engagingly sleepy-voiced straight man, and Voight hasn't seemed so wacky and optimistic since his never-say-die schoolteacher of "Conrack."

Ah, but the roll Voight's on quickly coasts to a stop. The first clue is Ann-Margret, a former lover of Kovac's now ensconced in the MGM Grand Hotel, but apparently still carrying a torch for him. In the Dr. Zhivago suite (the doorbell of which plays "Lara's Theme,") he takes her in his arms, quite blond and dashing behind his rakish mustache.

"Please . . . don't," she murmurs in tones resonant with ambiguity.

He doesn't.

Alas, it is not Ann-Margret's flame that has gone out, but Voight's. Try as he does, there is just no sustaining Alex Kovac's bubbly streetwise character through the dumb get-rich-quick scheme that follows -- a scheme built of cliche's and powered by the engines of coincidence. As Voight fades, the real problem of the conception becomes clear: To sustain characters at a fever pitch of wackiness that simultaneously advances the plot is a mighty tall order. That Alan Arkin and Peter Falk managed to do just that in "The In-Laws" does not make it any less tall an order.

As it happens, Voight shares the screenwriting credit with Al Schwartz. The word is that he offered the part to James Caan, Burt Reynolds, Peter Falk and Bruce Dern before accepting the job himself -- and then had to drop by Burt Young's house and put on a one-man show to persuade his co-star to sign. The screenplay does provide some entertaining dialogue on the order of, "If you rough me up, it'll be on your conscience," to which a thug replies, "What's a conscience?" What Voight apparently could not see, as co-author, was that at every other turn it strikes to the heart of the predictable.

Lamentably, Ann-Margret is given little to do except stand around like a .400 average pinch-hitter watching the team go down the drain. She's in uniform, she's in shape, why doesn't she get to play?

The director of "Lookin' to Get Out" is Hal Ashby, whose credits include "Coming Home," "Being There" and "Shampoo." His films have grossed a total of something like $250 million worldwide. That he lost his grip on this particular property is nowhere more evident than in the climactic scene in the casino, in which Voight, Young, Ann-Margret, the loan sharks and everyone else engage in a concluding free-for-all. The only way this scene will be considered a payoff is if patrons are given their money back.

More and more it seems that when all else fails, the director says, "Then let's make it zany."