A man went to his lawyer and told him, "My
neighbour 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."