Thanks Tony, I've never seen the movie (though I have seen a few other of Bogart's) and didn't know that it was from that movie (yes, I'm guilty too). I have never found the line particularly funny, but I always smile knowingly whenever anyone says it (so as to avoid the awkward moment of silence that immediately follows a joke if you don’t at least smile). I wonder how many people find the line funny for no other reason that others find it funny?