Three men walk into a bar and the barman says, ''If you can sit in my basement for a day I'll give you free beer forever.''

So the first man says, ''Easy. I can do that.''

But he walks out after five minutes and says, ''It's impossible, you got a swarm of flies in there.''

So the second man tries his luck, but can't take more than 10 minutes. Finally the third man goes in and comes out a day later. The others ask him how he did it.

He said, ''Easy. I took a dump in one corner and sat in the other corner!''