STEP RIGHT UP, folks! Don't be shy! What you are about to witness occurs just once a year! It's nothing less than (drum roll, please!) a kid's birthday party. That's right, ladies and gentlemen, it's that annual extravaganza in which your child and his friends are the stars of the show. No birthday on the horizon? Throw a Carnival Party as a fund-raiser for a Scout troop, school, or sports team. The big top's all ready, and tickets are going fast -- it's carnival time! Reasons to have a…