A barman in town finds a very expensive-looking pen and asks two Paddies at the bar if it belongs to them.

Paddy 1 says "Lend it 'ere a minute and I'll tell you"

He starts writing on a beer mat and says;

"Yep, it must be mine"

"How so?" says the barman

"'Cause that's my writing" he says.

:^O