Tomorrow's Great American Smokeout is directed at the 55 million Americans who smoke, but one of the keys to their success will be the support they receive from spouses, relatives, friends and coworkers. Studies suggest that smokers who have strong encouragement from the people around them are the most likely to succeed at kicking their habit for good.

"Show concern, but don't nag," says University of Orgeon psychologist Edward Lichtenstein, who has spent several years studying the effects social support has on smoking cessation. "Tell your friend or partner that you'd like them to quit smoking. Explain the reasons why it's important to do it, but don't overdo it or get preachy."

Also important, Lichtenstein says, is for the spouse or friend to realize that the early days of withdrawal could be tough. Being edgy or nervous can be part of the process. Minimizing stress is especially helpful.

"Try to relieve everyday hassles for them," he advises. "Communicate to the smoker. Ask what would be helpful for them in quitting."

Helpers may find that they have to tread a fine line between offering aid and nagging. Praise is helpful, but scolding and lectures are not. It's the difference, Lichtenstein explains, between complimenting someone for not smoking and commenting on their lack of will power if they slip and have a cigarette.

Written contracts between the helper and smoker work for some people. For others, establishing a system of rewards is useful. Experts advise focusing on activities or experiences, such as offering to do the dishes for a few months, as long as the smoker is not smoking.

A monetary incentive can also be helpful, says University of Pittsburgh psychologist Saul Shiffman. The smoker puts up an ante -- say $50 -- which is forfeited if there is a return to smoking. "Trying to stay off smoking is not enough," Shiffman says. If the person smokes even once, the money "should be donated to the smoker's least favorite" organization.

Most important, helpers need to realize that smoking cessation may not occur overnight, and there may be setbacks. "A friend or a spouse needs to realize that quitting smoking is a process," Lichtenstein says. Often smokers must go through several attempts before succeeding.

Other tips for helping a smoker quit include:

*Avoid lecturing smokers on the health hazards of cigarettes. Most are aware of the risks they face.

*Discuss the smoker's habit and how much he or she is committed to quitting. Offer to be available for daily contact, either in person or on the phone. Be positive in your comments.

*Be particularly patient and supportive during the early days of withdrawal. The first week is usually the worst. Experts say it is normal for those experiencing nicotine withdrawal to feel a little edgy, irritable or nervous.

*Don't nag or be suspicious. Don't assume that the quitter will fail, and don't put the smoker on the defensive by accusing him or her of smoking.

*When temptation strikes, remind the person trying to quit of all the reasons he or she chose to stop smoking. Again be positive. Experts recommend stressing the benefits of quitting -- saving money, getting rid of a morning cough, living without the smell of cigarette smoke.

*People who quit smoking find they have extra time on their hands. Volunteer to spend some of that time with the new ex-smoker, but avoid situations that make relapse easy, for instance, going to a party where people smoke or having a drink at a bar. Movies are a good bet, since smoking is usually prohibited in theaters. So is taking a walk, or any other form of physical activity that helps ease the nervous tension that often accompanies quitting. When out, encourage ex-smokers to take advantage of nonsmoking sections wherever provided.

*If there is a relapse, view the slip as a setback, not a failure. Help the smoker examine where it occurred, pinpoint what contributed to it, and think of ways to prevent smoking again in similar situations.

Finally, as the Minnesota Heart Health Program advises friends of smokers: "You can help your quitting friend remain an ex-smoker by keeping up the praise even after he or she has successfully kicked the habit."