A chemist walks into his shop to find a man leaning against the wall. 'What's wrong with him?' he asks his assistant. 'He came in for some cough syrup,' the assistant explains. 'But I couldn't find any, so I sold him a bottle of laxatives instead.' 'What!' the chemist says, horrified. 'You can't treat a cough with laxatives!' 'Of course you can,' t