Formal?! Pathetic mcdonaldisation of our culture. I ban formals.
You can have an end of term dance, you can drink heavily before hand, make a fool of yourself on the dancefloor, go home un-shagged and never enter your school again. You may not go in a helicopter or for that matter a "limo".
What is it with the school system trying to model itself on american high school movies? Don't forget if you're on Ocuk chances are you're a nerd and as such no helicopter is going to prevent the jocks from banging all the cheerleaders.