DEAR ABBY: Something happened yesterday that makes me want to stress the importance of bicycle helmets, even on toddlers who ride little ride-on toys. My 2-year-old daughter and 4-year-old son were riding their bikes on our sidewalk when my son accidentally bumped into the back of his sister's bike. The bike slid out from under her and she fell backward, hitting her head on the concrete. Fortunately she was wearing a helmet and was not injured, but I shudder to think what might have happened had she not been wearing one.

I always thought I was a little overprotective making my young children wear helmets when I didn't think they could get seriously injured in a fall from such a small vehicle. But I felt it was a good habit to get into for when they were older.

Now I'm grateful I listened to that "sixth sense" and avoided what could have been a serious head injury. We were lucky we were able to spend the rest of my husband's birthday having fun instead of sitting in the emergency room. I hope this letter will make parents think twice before letting their children, regardless of age, ride without a helmet. -- VIRGINIA BRIGGS, LEVITTOWN, PA.

DEAR VIRGINIA: You are a wise and conscientious mother for realizing that an innocent bike ride can be dangerous for children who aren't wearing bicycle helmets. Helmets can prevent an estimated 85 percent of serious head injuries, and greatly reduce the risk of severe brain injury that can result in death. However, even a minor brain injury can lead to problems with learning and memory.

There are many good helmets on the market today. The easiest way to find one that is well made and reliable is to look for the "SNELL" certification sticker. Helmet models carrying that decal have met rigorous standards in tests performed by the Snell Foundation. Based on three decades of research in the United States and England, a Snell-certified helmet is one of the best.

Bicycle helmets save lives. There's no better reason to insist that your child wears one.

P.S. Helmets are also essential safety gear for other sports such as inline skating, etc.

DEAR ABBY: I've got a big problem. It started when my friend "Raymondo" got a divorce and left for New York with his new wife and his daughter last spring. We kept in touch with them for a while, and Raymondo kept saying he didn't like living up north and he wanted to return.

Finally he left his new wife and returned with his daughter. However, he had no place to live because he has no family here in the United States, and his former wife's family wanted no part of him.

We told Raymondo he could stay with us until he found a job and earned enough money to rent an apartment. A month passed. Two months.

Abby, he is still here with us, using our water and electricity and eating our food. He doesn't pay for anything. How can we tell Raymondo to leave? -- FERNANDO IN FLORIDA

DEAR FERNANDO: Tell him in Spanish. If that doesn't work, tell him in English. But whatever language you use, "talk turkey" by making it clear that he has worn out his welcome and he must be out within two weeks. Then stand by your decision.

For everything you need to know about wedding planning, order "How to Have a Lovely Wedding." Send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Wedding Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: Yesterday I went into a store that was having a sale. While I was there, I saw some tables that had decorative items for 50 percent off. I found two things I wanted. The sale amounted to less than $20, so I paid cash for them.

Before the salesman gave me my purchase, he demanded my name, address and telephone number. Abby, this was a cash sale. He held my purchases until I reluctantly gave him my name and address. (I steadfastly refused to give him my telephone number, since it is unlisted.)

This isn't the first time I've had this happen with a cash sale. What in the world are businesses thinking of? If I pay cash for something, why should I be obliged to give them this information? I strongly object to this practice. It is an invasion of privacy.

I would appreciate it if you would publish this letter. Businesses that do this should be aware that they may have lost any future business from this particular customer. If I must give this kind of information when I make a cash purchase, I'll shop someplace else next time. -- DISGUSTED SHOPPER, FORT MYERS, FLA.

DEAR DISGUSTED SHOPPER: Some places of business do this because they want to add your name to their mailing list. However, you are under no obligation to give personal information -- and in the future you should tell the store manager how you feel about it.

DEAR ABBY: I read the excellent letter from the Carrollton, Ga., librarian, encouraging people to ask for help at the public library. May I add another suggestion?

As a children's librarian, I wish more families would bring their kids to the library and explore all the wonderful services we have to offer them. With the current prices of family entertainment, many parents would be pleasantly surprised to discover the free materials and programs that are available at their public library.

Consider the fun of attending a puppet show and taking home books and videos, or bringing the children to an evening story-time and browsing through magazines and tapes after the program.

Mom or Dad can drop by the library after work, and in a few minutes head home with a whole evening's fun for the family.

The public library shouldn't be "the best-kept secret" in your neighborhood. Please come by and ask us what we can do for you. -- MISS JUDI IN DALLAS

DEAR MISS JUDI: Thanks for a valuable suggestion. I'm pleased to give it space in my column. Your love for your profession is reflected in every paragraph of your inspiring letter. Read on:

DEAR ABBY: Regarding the librarian who was helpful and enjoyed answering questions -- I only wish she worked in our city library.

I have never seen our librarian get out of her chair. She sighs, rolls her eyes, and gives directions by jerking her thumb over her shoulder. All this is accomplished without uttering a single word. -- STILL SEARCHING IN RICHLAND, WASH.

DEAR STILL SEARCHING: If you're still wandering through the stacks, start searching for this woman's boss and repeat what you have written to me. Your librarian needs motivation, and I hope she receives it before she drives away the people she's paid to serve.

To receive a collection of Abby's most memorable -- and most frequently requested -- poems and essays, send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby's "Keepers," P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)

DEAR ABBY: For several years I have wanted to share this little trick for parents whose small children consume too much candy at Halloween. Finally, I've found the time to write, and it's actually BEFORE Halloween.

I have always told my children, thanks to Linus in the "Peanuts" comic strip by Charles M. Schulz, that the Great Pumpkin comes on Halloween night and brings a gift for the children who leave him candy. The more of their candy they leave, the bigger the gift is. To make this work -- and my children have never kept more than five pieces of candy -- you must begin when the children are very young, and keep reminding them that the more candy they leave, the BIGGER the gift. When my children keep only five pieces and turn the rest over to the Great Pumpkin, they get a substantial gift that they really want.

It's worth it to me. My kids have never had a cavity. And my husband and his co-workers are more than happy to eat what the Great Pumpkin reaps. I hope this works for other families. -- NO SUGAR IN SEATTLE

DEAR NO SUGAR: What a "sweet" idea for parents who try to limit their children's sugar intake. It's a suggestion I'm sure many parents will welcome this Halloween.

And while I'm on the subject of Halloween, may I add a few more tips from the National Citizens' Crime Prevention Campaign, which is substantially funded by the U.S. Department of Justice:

1. Instruct children not to eat any treats until they get home. Feed them a meal or snack before they go out to keep them from digging in while they're out. Parents should inspect all the treats.

2. Allow children to eat only those treats that are in unopened and original wrappers. Carefully inspect fruits and homemade goodies.

3. Make sure children wear light colors or put reflective tape on their flame-retardant costumes, which should be short to prevent trips and falls.

4. Try makeup instead of masks, which can obstruct a child's vision.

5. Children should trick-or-treat in groups, and stop only at familiar homes where the outside lights are on. Young children should always be accompanied by an adult.

6. Map out a safe route to familiar homes for older trick-or-treaters, and make sure the children have flashlights, and that they stay on well-lighted streets.

DEAR ABBY: Your letter to "Sleepless, But Not in Seattle," struck a familiar note with me. My natural sleep rhythm also makes me a night owl. I have been like this as far back as I can remember, going to bed after midnight and waking up around 10 a.m. I was always teased about it, and my mother used to stand at the bottom of the stairs and sing, "Lazy Mary, Will You Get Up?"

Now that I'm an adult, I get the same attitude from my husband. He's snoozing in his recliner by 8 p.m. (nobody says he's lazy), and I'm wide awake for four more hours. I even wear a nightshirt that says, "Perky Morning People Should Be Shot!"

I don't know why "Sleepless" should be considered to have a "condition" that can be relieved. She's fine. She should find a job on the second shift and work from 3 p.m. to midnight, or work the swing shift. She'll be glad she did. No sense dragging around, waiting for retirement to enjoy life. Sign me ... SLEEPLESS IN LOUISIANA

DEAR SLEEPLESS: If other factors in "Sleepless's" life don't compel her to conform, that's certainly an option worth exploring.

Good advice for everyone -- teens to seniors -- is in "The Anger in All of Us and How to Deal With It." To order, send a business-sized, self-addressed envelope, plus check or money order for $3.95 ($4.50 in Canada) to: Dear Abby, Anger Booklet, P.O. Box 447, Mount Morris, Ill. 61054-0447. (Postage is included.)