What do you say when someone knocks on the bathroom cubicle door?

When a toilet stall or cubicle is closed, you know what that means. It means it is occupied. Apparently, not all people share this understanding. Imagine you're doing your thing in a public bathroom (like the one at work) and suddenly someone knocks on your door. The exchange could go a little something like this: "Knock-knock." "Who's there?" "Oh, there's someone inside the bathroom?!" "Yes, that's why it's closed and locked." "Oops, my bad." Take a listen to hear Vic Naidoo's thoughts on this very specific situation.