... or the door must be a sliding door.

Unlocked sliding door foils robbery attempt:

www.abc.net.au/news/2004-11-22/unlocked-sliding-door-foils-robbery-attempt/589438

Three would-be robbers tried to kick down the door of a restaurant on the south coast of New South Wales last night, not realising it was an unlocked sliding door.

It could have been a rehearsal for a slapstick comedy but police are taking it seriously.

Acting Senior Sergeant John Klepzcarek says 20 bemused patrons inside the restaurant at Gerringong watched as the three men, wearing balaclavas, tried to kick open the glass door.

"Three men allegedly had hoods covering their faces, one was allegedly armed with a knife," Senior Sergeant Klepzcarek said.

"The man with the knife attempted to push to open the glass sliding door.

"Because it wouldn't open, he started kicking it. One of the other men tried to push the sliding door and after a number of attempts all three men have run off," he said.