I had close friendships 20 years ago with some people who have since become what are classified as "the homeless." At the time, they were at least employed. We shared views and common experiences, including drugs, which I no longer share.

I do not feel guilty in any way for having chosen a drug-free life of personal responsibility and career advancement. I know how these people have preyed on others and how they abused agencies that were established to help people who really had no resources.I will not give money to these people. I hang up on them if they call, and I avoid them.

However, I have recently begun working in a job where I have contact with the public. I have seen these people when I have been working with both subordinates and bosses. So far I've managed to avoid recognition, but it's only a matter of time.

If I am confronted, how do I explain to those who trust my opinions and values that I ever had anything in common with people who absolutely mortify me now?

GENTLE READER - Miss Manners is sorry for the fear that you have of ghosts from your past, but urges you to remember that people do not so easily divine an entire history from one clue. The natural assumption, if one of these people greeted you, even with hostility, would be that you had attempted to help them in the past. Many formerly respectable people having been sadly reduced to such circumstances, one could also assume that the friendship dated from times when neither of you were in bad circumstances.

You may or may not want to let that stand, depending on whether you are with business associates or friends when it happens. While there are people in your private life you will confide in, it is foolish and inconsiderate to do so with mere acquaintances.

If approached by a former friend, you need only respond kindly, "Good luck to you," and explain only to anyone else that you used to know that person.

DEAR MISS MANNERS - I am an artist living in a small cottage, which I refer to as my art studio. I also have a job in the city unrelated to my art. I paint when I get home, and I spend quite a bit of money on art materials.

Whenever my friend visits me, she is supportive of my art and says how beautiful it is; then she asks me if she can "have it."

I am astonished at the thought of going into someone else's home, even if it is an art studio, with paintings for sale, and asking to have something that belongs to the person who lives there. Obviously some people think that art is free, without any regard to the many hours and the large amount of money that went into the final result.

I just want her to know that if she has the money, she can have it; however, as my friend, she cannot expect me to give a painting to her for nothing (as I have done before).

GENTLE READER - Your having given your friend a painting more than once weakens your case about her effrontery in asking for a particular one, Miss Manners is afraid. The friend is still wrong, even brazenly so, but you seem to have abetted the idea that painting is a hobby of yours, and that since the pictures are intended as tokens of friendship, it is a help if she indicates which she likes best.

It is time to stop giving this particular friend such presents. Find something else to give her when the occasion arises. As for the occasions she creates, you need only say, "I'm glad you like it - I'm hoping to get (whatever price you have set) for it."

In a dilemma about giving or receiving pres-ents? Help is available in Miss Manners' "Present-Giving" pamphlet. Send $1.50 to Miss Manners, in care of this newspaper, P.O. Box 91428, Cleveland, OH 44101-3428.

1990, United Feature Syndicate, Inc.