the name of the song is nothin but a good time its a cover version originally done by poison don't know who's doin this version though ive been trying to find it for a while myself.
It's "Nothin' But a Good Time" by Poison. It's from "Open Up and Say Aah". It's a dodgy glam rock/metal song from the early 90's, so it's a bit different from a bunch of school kids.
I couldn't believe they used that song in the advert, but thankfully it stops just before the line "Well, I spend all my money on women & wine, I couldn't tell you where I spent last night".