Funny and smart

A man went to his lawyer and told him, "My neighbor owes me $500 and he doesn't want to pay up. What should I do?" "Do you have any proof?" asked the lawyer. "Nope," replied the man. "Okay, then write him a letter asking him for the $1000 he owed you," said the lawyer. "But it's only $500," replied the man. "Precisely. That's what he will reply and we will have the proof we need to nail him."