It's a classic "ad-scam:" An item is advertised on sale at a terrific price, but when you arrive at the store, a sales clerk tells you that the item was just sold out, or is of very poor quality.

"That's the 'bait,'" consumer counselor Onra Dillard told participants in a consumer counseling session at a Southeast Washington senior center. "It has brought you into the store, and you have already made up your mind to buy it."

The "switch" part of a "bait-and-switch" scheme, she said, comes when the salesperson trys to get you to switch to a more expensive model, or to another item in the store.

"Legitimate merchants will almost always give you a rain check on the advertised product," she said. "If the ad mentions a limited quantity, call the store to make sure the item is still available. Many times a merchant will set one aside for you."

Dillard's workshop on fraud and deception practices is part of an eight-week Fixed-Income Consumer Counseling program sponsored by the University of the District of Columbia's division of continuing education.

Funded by a $35,000 grant from ACTION, the project trains community volunteers in economic counseling of the elderly, the disabled, welfare recipients and other District residents living on fixed incomes.

The Capitol View Plaza Senior Citizens Center is one of about 50 counseling sites around the city, said project director Cynthia Bryant. Current topics include consumer protection, health, housing, credit, banking and budgeting, with plans for others, like comparison shopping and thrift-store shopping.

"We still need volunteers," said Bryant, "particularly those with expertise in these areas, like a retired lawyer, accountant or nurse."

Older people are often the target of deceptive practices, said Dillard, 60, a retired Navy Department supply officer, "because we're so trusting. We often assume that people will be as honest as they were when we were youngsters. But, unfortunately, we have to be aware that the world has changed."

Her "10 commandments for consumers:"

1. Always get the name of the person you're talking to when doing business by phone.

2. Inspect an item before you take it home -- particularly if it comes in a sealed box.

3. Don't allow yourself to be pressured. Refuse to deal with sellers who say you must buy now. When undecided, ask the merchant to hold the item for a few hours while you think it over.

4. Never buy for price alone. Clerk to see if the price includes service and delivery charges, and comparison-shop to be sure you're getting the best value.

5. Read all signs, labels, advertisements and guarantees, especially the fine print.Be aware that spoken promises are not legally binding; get them in writing.

6. Never sign a contract with blank spaces. Don't sign until all your questions have been answered.

7. Seek advice from trusted friends or professionals before spending or investing large sums of money.

8. Make sure you really want or need what you're buying and that you're not going to be sorry the next day.

9. Try to deal only with businesses with solid roots in your community.

10. Never expect to get something for nothing. It is one of the oldest -- yet successful -- ploys used by shady businesses to take your money.