POD to the previous posters. Explain your expectations before the guests arrive, and be prepared to address misbehavior if it comes up. I like the suggestion that the kids be given a chance to show one skill or possession, assuming a proper audience (Grandparents, aunts & uncles, yes. Your husband's boss, probably not so much.) As for addressing the misbehavior, you can use codewords, use the 1-2-3 method, or whatever works for your family. If your child continues to misbehave, excuse yourself, take the child out of the room and address it out of earshot of the guest. No one likes to be embarrassed. This will minimize the embarrassment for you, your child, and your guest.