Etiquette books, as far as I know, will tell you how to behave when your friend gets married, buried, graduated, or hospitalized.

But let's say your friend, who always seemed sensible and predictable, tells you she's quitting her job. Sure, it's a good job, she says, but she dreads getting up for work and she's stressed. Her medical bills have risen along with her salary.

You suggest, as delicately as possible, that she get "professional help." She tells you she's hired a coach and a business consultant, and no, she isn't starting a baseball team. She has a new business. You don't know whether to laugh or cry.

Here are a few suggestions to maintain the friendship.

1. Do not call your friend after two weeks to ask, "So, made any money yet?" This will be a sore subject for the first six months or more. And remember: dollar amounts are relative. Your friend who previously earned ten thousand dollars a month will be ecstatic when he sees five hundred. Dollars, that is, not thousand.

2. Choose gifts with sensitivity. Best bets are gift certificates at mega-stores, preferably online, so your friend can buy anything from software to books. A gift certificate for coaching, computer maintenance or office supplies will be appreciated.

Dinner at a nice restaurant will go well if you can persuade your friend to leave her beeper and cell phone at home. Just one warning: The sight of a computer on the restaurant desktop may trigger the urge to check for email. Remind your friend firmly: the messages will still be waiting after dessert.

3. Offer support when your friend feels discouraged. "Well, you won't lose much if you pull out now" is about as insensitive as you can get. Friendly questions include, "Are you seeing signs of progress?" Better, take your friend to a movie and suggest he call his coach afterward.

Whatever else, do not say anything like, "You might as well spend the money now. You won't have more later." Or, "I heard the person who replaced you just got another raise."

4. Expect your friend to keep weird hours. You just got a call at eleven o'clock at night? Or five in the morning? Never fear, there's no emergency. Just routine business hours for the self-employed.

5. Allow your friend to change her mind. Some people who start a business realize they miss corporate life. They may decide they want to take a job for awhile, to increase their stash of cash and gain some additional experience.

That's when true friendship comes through. Saying, "I told you so" is a major taboo. And, "I knew you wouldn't make it" will kill even the most solid friendship, as soon as the words are out.

I offer one-to-one consultations for anyone considering starting a business.