"Single Bars, Single Women," the ABC Sunday Night Movie, is a collection of vignettes about people looking for That Certain Someone with whom to spend, oh, the next eight hours or so. It's sort of a yuppie "Saturday Night Fever" -- one character even has a brother who's a seminary dropout -- without the dancing.

Not very intuitive, nor original, the film (at 9 p.m. tomorrow on Channel 7) gets by on the basis of performances by Tony Danza, Shelley Hack, Mare Winningham and Kathleen Wilhoite (who has an adorable smile), but especially Christine Lahti, who is crisp and smart and touching as Elsie, a 35-year-old schoolteacher whose trip to Bandini's singles bar, the setting for most of the story, will be her first.

"Half the school thinks we're a pair of contentious old lesbians," Elsie complains to her colleague and roommate, and off she goes looking great to the bar, where she meets Max, who's married, and who she dumps before he can start the car in the parking lot to take her to a motel. Rebounding, she encounters Danza as Dennis, a big playful puppy whose emotional demands are that there be no emotional demands.

Elsie invites Dennis to her living room couch, but when he makes his first programmed moves, she begins laughing uncontrollably. And then crying, but controllably. Writer Michael Bortman doesn't get the scene much past Today's Banalities, but Lahti takes it further. She breathes magic into it and it sparkles. None of the other characters or story lines can compete.

Harry Winer directed, bobbing and weaving around the bar to pick up the characters as they try to pick up each other. The film was "inspired by" the tune that gave it its title, one sung by Dolly Parton and written by former "Saturday Night Live" writer and self-styled bad boy Michael O'Donoghue, who is also listed as co-executive producer.

Others in the cast include Paul Michael Glaser, Keith Gordon (all too suitably cast as a transfixed wimp), and in a tiny cameo that registers strongly, Jessica Nelson as Sonia, who thinks she isn't pretty and despairs to find her opinion confirmed by others. The movie is not so empty as many TV films, but it retreats from the new ground it once or twice threatens to break and ends up safely trite. 'Countdown to Looking Glass'

One way to get attention is to blow up the world. ABC did it with "The Day After," NBC did it with "World War III," and now Home Box Office, the pay-cable network, enters this noisy fray with a speculative pseudo-docudrama called "Countdown to Looking Glass." It's the dullest Armageddon yet.

You know you're in trouble with a doomsday thriller when 20 minutes in you're already saying, "Okay, let's get on with it! Let's get those missiles up!" An uneasy hybrid of think-tank position paper and portentous melodrama, the program chronicles nine imaginary days that lead up to nuclear confrontation in the Persian Gulf. Most of it is done through simulated newscasts -- a device borrowed from last year's much superior NBC production "Special Bulletin," about nuclear terrorism -- and the prevailing spirit is that global politics are one big chess game that could go goofy at any moment.

The one innovation, such as it is, of the HBO show (whose first air date is Sunday, with many more exposures to follow) is that it features some media personalities and public figures playing themselves. Eric Sevareid and Nancy Dickerson, who both once worked for real networks, keep popping up on behalf of the fictitious "CVN" network covering the big story. Also seen are former U.S. ambassador to NATO Robert Ellsworth, retired admiral Gene R. La Rocque, and former chief U.S. negotiator at the SALT talks Paul Warnke.

And there's more: former senator Eugene McCarthy on the left and on the right, Rep. Newt Gingrich (R-Ga.), who coincidentally or not is one of the very least camera-shy members of the House. As the simulated dominoes fall, McCarthy says things like, "I think we have to go very slowly on this matter" (no problem there for this film), and Sevareid says, "Well, it's serious all right -- very serious," and Gingrich says, "There is no 'thing' worth nuclear war, but Winston Churchill said it brilliantly when he said, 'War is horrible, slavery is worse.' "

The viewer also gets to hear from MIT professor Lincoln Bloomfield, who happens to have written the convoluted war-game scenario on which the script is based. Among the professional, though not necessarily more convincing, actors appearing are Helen Shaver as a TV correspondent named Dorian Waldorf, Michael Murphy as her boyfriend, a top White House aide, and Scott Glenn as a reporter who eventually witnesses the exchange of nuclear weapons in the Gulf. Patrick Watson, as Dan Tobin, makes so boring an anchorman that dour Sevareid is a house afire by comparison.

According to the hypothesis presented here, nuclear war becomes nearly inevitable after a chain of events that starts when three South American countries go broke, causing bank failures in the United States and extreme testiness in Mideastern countries that had heavily invested in those banks. Then this happens, and that happens, and in the midst of it all, the secretary of defense drops dead in the White House. This doesn't contribute to the problem, but it's meant to illustrate how much tension people in such circumstances would have to bear. Bloomfield gets to state the author's message: "We spend billions on machinery for crisis management, but what's inside people's heads is the same old equipment, and I think this is a terrible problem."

Yes, we should spend billions developing better brains.

Before "The Day After" was shown, conservatives railed that it was another liberal tract from Hollywood, but neither conservatives nor liberals are likely to get very agitated about "Looking Glass." For one thing, both of them are represented within the program. For another, it not only doesn't take a very strong stand, it barely stands at all. One good breeze would blow the whole thing away.