That reminds me of the things we did as apprentices. Most office blocks used to have a licenced bar in the canteen ( oh yes, they encouraged drinking back then). Anyhow, when they locked up, they pulled down a type of roller shutter grill thingy. We used to get a length of Unistrut, and poke it through and pivot it on the grill so one end was under the optics and the other end, a large mug...... Free spirits .I think I left it there when I was trying to figure out the combination lock to get in and nick some of your beer!
But you've changed the locks again since last week..
you sneaky Bu***r! X( :_| :_| :_|
This lasted months until the plumbers messed it up for us by putting a sharp nail on the end of a pipe and stabbing the **** at the back. Unfortunately they often dropped the pack and we all got sussed out X( .