A case of give and take

A man and his wife were getting a divorce at a local court.But the custody of their children posed a problem.
The mother jumped to her feet and protested to the judge that since she had brought the children into the world,she should retain custody of them.

The man also wanted custody of his children.The judge asked for his side of the story too.

After a long moment of silence,the man rose from his chair and replied,"Judge, when I put a dollar in a vending machine and a Pepsi comes out,does the Pepsi belong to me or to the machine?"