A man and his young wife

A man and his young wife were in divorce court, but the custody of their children posed a problem. The mother gets up and says to the judge that since she brought the children into this world, she should retain custody of them. The man also wanted custody of his children, so the judge asked for his justification. After a long silence, the man slowly rose from his chair and replied, "Your Honour, when I put a dollar in a vending machine and a Coke comes out, does the Coke belong to me or the machine?"