John was a clerk in a small drugstore, but he was not much of a salesman. He could never find the item the customer wanted. The drugstore owner had had about enough and warned John that the next sale he missed would be his last.

Just then a man came in coughing and asked John for their best cough syrup. Try as he might, John could not find the cough syrup. Remembering the owner's warning, John sold the man a box of Ex-Lax and instructed him to take the entire box all at once. The customer immediately consumed the entire box in the store and then walked outside and leaned against a lamppost. The drugstore owner had seen the whole thing and came over to ask John what had transpired.

"He wanted something for his cough but I couldn't find the cough syrup. I substituted Ex-Lax and told him to take it all at once." "Ex- Lax won't cure a cough!" the owner shouted angrily.

"Sure it will," John said, pointing at the man leaning on the lamppost. "Look at him. He's afraid to cough."