To serve or not to serve   Thursday, June 14, 2007   By Gretchen McKay, Pittsburgh Post-Gazette   Alcohol is a given at many neighborhood and family parties, be it a keg or an icy pitcher of sangria. But should it be on the menu at your teen's graduation party?   Knowing that kids will be kids, it's probably something you will want to avoid, says Ginger Venable, co-author of a book on graduation parties who also runs www.graduationparty.com. Local laws vary, but party hosts can be held liable if a minor gets drunk at their house and then gets into a car accident or injures someone on the way home.   Kids probably won't care if their party's dry, but what about the grown-ups? One way to keep a party alcohol-free without anyone really noticing, says Ms. Venable, is to make it a brunch or throw the celebration in the afternoon, when most adult guests aren't really expecting to drink. Or you could save the margaritas for later, after the kids have moved on to other activities.   If you do choose to serve alcohol, keep it completely separate from the soft drinks and other nonalcoholic beverages, and mark the designated table or area with streamers or balloons. You'll see if kids are lingering where they shouldn't. You'll also need to assign a responsible adult as bartender.   Because it's pretty easy for a kid to slip spirits like rum and vodka into a soft drink unnoticed, you might also consider limiting alcoholic offerings to beer and wine. Also, use clear plastic cups so you can see what people are drinking.   Finally, make sure guests know when they arrive that you do not tolerate underage drinking. That includes the adults, who might harbor a "what the heck" attitude.   And don't be afraid to look in a teenager's glass or smell his or her breath if you have any suspicions.