Well, as Ann Cookmeyer said shortly after Allen Walkup and Shirley Swink got married in the Springfield Mall Shopping Center, "What's a wedding? You see all these great big church weddings, all fine and fancy, and a month, a year later, they're over.

"Marriage," she said, in the way of a woman who knows what she knows, "is a lottery."

But on Saturday night, it was a conjoining of elements wondrous to behold, a truly suburban song-two native northern Virginians, bound in martrimony in a shopping mall, courtesy of the great American PR machine and the time-honored need for custom and ceremony, even in this age of dissonance and disco.

Shirley and Allen Walkup both work for the CIA. She is 29 and in "an upward mobility program," that should land her a GS-9 in September. He's 35 and has been a computer programmer there for 14 years. Last month they won a contest in which they had to explain, in 25 words or less, "Why I Want to Get Married in Springfield Mall." The answer was simple enough. Money.

"We didn't have the money to get married big," Shirley explained with the kind of unabashed honesty that lent the whole affair its own intrinsic logic. "But we wanted a big bash that we could invite all our friends to and we wanted something unique."

Water skis were ruled out-the timing could be a lttle tricky. A cruise up the Potomac was too expensive. But an all, or nearly all, expense-paid wedding in a shopping center? "I read the ad in the paper and thought 'wow, now this is really wild,'" said Allen Walkup, as his eyes kindled.

There were over 1,000 entries, according to Alison Russell, who does public relations for WKYS,a disco radio station, that was cosponsor of the event. And the choice wasn't easy.

Not, after all, when you have a couple of 40-year-olds who want to get married again to prove to their children that the institution still endures in this ephemeral world-and then, of course, there were the Marines.

The Marines were really tempting, Russell said. "But how could you pass up the CIA-they couldn't work for a more closet organization. Actually, it all tied up in a nice pretty bundle-love and disco in the shopping mall. The themes are just great."

Indeed they were. For years now, since shopping was converted from a necessary nuisance to the latest expression of the pleasure principle, the megacenters have furnished a focus for traditions and rituals that suburbs separated by superhighways could not supply. Down the long, climate-controlled corridors, among the glittering boutiques, there exists a refuge for the arcane rites of adolescence, for the unblinking vision of the old, for the merely lonely seeking a narcotic in numbers. A wedding? Of course.

The merchants of Springfield Mall supplied just about everything for the ceremony, from the dress, flowers and the white plastic cloth, which formed a canopy and festooned the stairs leading down from Garfinckel's from which the bride was to make her entrance, to the minister-Don LaRue, a former Baptist minister turned Fairfax county real estate salesman, who freelances weddings on weekends.

Allen Walkup gave him four Corvette hubcaps as a token of his gratitude and in honor of a commonly held passion for cars.

There was also the honeymoon in Acapulco, which the Walkups won't take until May, but which, courtesy of American Express, will land them in a honeymoon cottage complete with private swimming pool and a little pink Jeep in which to see the sights.

All of this glory exacted a certain price from the Walkups, of course. They had to agree to any and all publicity and to the presence of several hundred stray shoppers who would be there to witness their wedding. Shirley didn't mind. "I love him," she said. "I don't care if the world knows."

There were limits, however. They said no to holding the wedding at high noon, the mall's equivalent of Beltway rush hour. Shirley wanted to make sure that the Garfinckel's sign and the Sticks N' Wicks insignia were tastefully masked by potted plants for the wedding pictures. And Shirley's hairdresser put his foot down at idea of J. C. Penney's doing her hair. "He said, 'If you let them do it, you'll look just like Dolly Parton, and don't blame me,'" said the new Mrs. Walkup, who tends toward a modified Farrah Fawcett-Majors.

The wedding party was not worried about the possiblity of rampant commercialism clouding the seriousness of the ceremony. Quite the contrary.

"This is the way to go," said bridesmaid Lorraine McGinnis, who was married in 1951 in the most traditional of ceremonies. "Look at it this way-you're a bride, you get all dressed up and shell out all that money to be the center of attention for 15 to 20 minutes and then it's all over. This way is much better. This way the whole world gets to see you."

And Doug Hewitt, a Park policeman and childhood friend of the gromm, agreed. "With inflation what it is today, it's real risk getting married-the whole thing's pretty shaky, you never know if it's going to work out. But getting married in a shopping mall is a once-in-a-lifetime thing."

By the time the ceremony began 20 minutes later than it was scheduled, due to the late arrival of a local television station's camera crew, hundreds of shoppers had gathered to gawk. Shirley soon-to-be-Walkup descended the staircase to the organ's version of "Cherish" and had all the radiance and beauty prescribed for bride.

Allen looked perfectly petrified, until the two stood together under the canopy where they said their vows into the microphone with the television cameras whirring away. Their voices were drowned however, by the hum of the marketplace-a wedding is a wedding, but a satisfied customer is a sale.

hrough it all, they looked very much in love. And when Don LaRue pronounced them man and wife there were sighs and applause from the guests (invited and otherwise).

After a brief interview in front of the cameras, they left the ceremonial site and the bright white lights followed them out, past Fannie May's and Fancy Tee's, and Hickory Farms and the Tobacco Barn. Past Gags, Gadgets and Gizmos to the Ford LTD waiting to take them to the Springfield Hilton, which seemed to be having a sale on wedding receptions, given the number that were held there that day.

Reviews among the bystanders were mixed."ridiculous," harrumphed several shoppers. And Georgiann Yates, who is 20 and getting married next month in a church, thought it was outrageous. "It's just not very personal to have the whole world at your weddung," she said, looking very young and very sincere.

"I think," said one man in a Banlon shirt, "that it was a very natural thing to do. After all, people spend a lot more time in shopping centers than they do in churches."

So nonchalant an attitude was harder to come by for Allen Walkup's father and stepmother. Homer and Charlotte Walkup were fairly "freaked out," as their son put it, when he announced his intention of getting married in the shopping mall.

But as the reception prepared to get under way, complete with a disco sound system and a deejay courtesy of WKYS, Homer Walkup found his answer in wry resignation. "It is a bit on the unusual side," he said. "But then, the whole family situation has changed. There are girls living with girls, and boys living with boys, and some of them want to adopt children. What does one do but accept?" CAPTION: Picture 1, The Walkups' wedding in Springfield Mall, by James A. Parcell-The Washington Post; Picture 2, Shirley and Allen Walkup, by James A. Parcell-TheWashington Post