From a little known Scottish sitcom 'The Highlife'
*Knocking on toilet door, opened by cabin steward*
Steward: Are you OK Captain Duff?
Captain: Well no I can't find the instruments or the ruddy co-pilot!
Steward: You're in the toilet sir!?
Captain: What the hell am I doing in there?
Steward: I don't know but I hope for your trousers sake you've finished!