IT's the day of the big party and you had it all figured out. You would leave work early, go to the hair salon and head home to change. But you didn't count on this being the busiest work day of the year. Projects kept you hopping. You missed your hair appointment. Now, with less than an hour before your function, going home is no longer an option. You have little time to do anything but dash to the affair.

So here's your challenge: You've got just minutes to transform your business look to one that's after-five. Feeling a little queasy? If you had planned ahead, you'd be able to relax. Experts say it doesn't take much. With a few adjustments, you can go from being a corporate diva to being the belle of the ball. No fairy godmother required.

Kya Robottom, an obstetrician/gynecologist, is an expert at quick changes. During the day, the Chicago physician wears a lab coat over conservative suits in classic colors such as black, brown and blue. Like others in her field, she chooses subtlety over flash. That means wearing loafers or pumps, demure earrings, little makeup and a simple hair style.

"As a Black woman, I have to dress a certain way to ensure the respect of my peers," says Dr. Robottom. "The patients also expect a certain image to be upheld.

The hospital is very conservative. It's the Brooks Brothers set. If you can find it there, it would be fine to wear here."

Evenings, however, she lets her fun side show. On a night out with the girls, Dr. Robottom might don a beret or a funky pair of boots. Shifting from her day-to-evening look might seem hard to manage on the fly. But the physician says if she has a special event after work (such as a date or cocktail party), she finds simple ways to transform her look.

That might mean applying a darker or brighter lipstick and bolder eye makeup, putting on more dramatic earrings and selecting a sassy purse. If she didn't wear a necklace to work, she might put on a diamond pendant for an evening outing.

"I might just change to a funky sweater over plain trousers," Dr. Robottom adds. "Or put on a hat."

Those techniques are on the mark. The key to a quick transition is to find ways to distinguish between your business look and your party look.

"You have to remember to keep the two looks separate," says a Detroit fashion expert. "You never want to look like you're dressed to attend a cocktail party at the office. And in reverse, during an after-five affair, you don't want to create the feeling that you just left a long and tiring business meeting."

You achieve that separation by embracing an attitude of fun and play. Experiment with shoes, purses, scarves and earrings to alter the statement your attire makes. You can switch from pumps to strappy heels, exchange a briefcase for a cocktail bag, add a classy or glittery scarf or put on an eye-catching pair of earrings. All it takes is a few accessories and some imagination. A change of your hairstyle also can help indicate a different attitude. If you wear your hair in a bob to work, try a chignon for the evening. Hair worn in an up 'do at the office should be taken down for evening events. Glittery hair ornaments add just the pizzazz to put you in the mood for fun.

When building your business wardrobe, remember that versatility is of utmost importance. Invest in jackets, shells, skirts and blouses in classic styles. As you plan your daily outfit, consider how you might quickly change the look for a social outing if necessary. Perhaps you could wear a camisole underneath a suit. If an after-work event comes up, you could remove the jacket, add some jewelry and--voila! --a new you. Or perhaps you could wear a twin-set with a pair of pants to the office. Twin-sets give you several options for quick changes. You can remove the sweater and wear just the shell. Or jazz up the sweater combination with sparkly jewelry.

Another tip is to keep a survival bag at work that's filled with the essentials for fast transformations--vibrant lipstick, dramatic eyeshadow, costume jewelry, scarves, hairpins and accessories, and an emergency pair of stop-and-stare shoes. Keep your look simple and classic during the day so you can express yourself in the evening. Mastering the quick change can be challenging, particularly for women whose social calendars rival their business agendas. But with some planning and some creativity, you can become an expert at looking great, no matter the time crunch or the occasion.

Eight Essentials For A Quick Change

* Little Black Black Dress: Can be worn with a blazer to the office, provided the dress grazes the knee or below. You can remove the jacket for after-work outings and add some spice with jewelry or a scarf.

* Jewelry: Pearls, rhinestones, gold, silver, African accents, attractive costume jewelry. The more options, the better. You want to make sure you have plenty of options--think earrings, chokers and bracelets--to help you dress-up your business look.

* Shoes: Leather pumps for day, strappy high heels, knee-high boots or satin slippers for evening. Changing your shoes can give you just the edge to pull off a snappy transition.