drew: Do you want to do the restriction with only R rated movies or for all movies? If you want to do it for all movies, then you are bound to loose a lot of money as the teen crowd make up a very large demographic of frequent movie goers (take a look at
www.mpaa.org for actual statistics). I know you probably don't want to drive away your other patrons who are being bothered by teens, but for every bad teen you've kept out of the theater, there are probably 3 or 4 good ones that you've kept out as well. Also, how many teens are going to want to watch a movie with their parents?
About the best you can do is keep an eye on them when they came into your theater. If they are being disruptive, give them a warning and then kick them out; if you have to, call the police and have them escort the teens out. If it's a particular group of teens that are causing you trouble, then deny them entry into the theater. Perhaps missing a really big movie will make them realize that they need to get their act together. Hope this helps.