The secret formula for creating New Yorker cartoons

Last year MM gave me a copy of The Complete Cartoons of The New Yorker, an impressive tome that boasts 2,004 cartoons. The cds that accompany the book contain all 68,647 cartoons from the magazine's 80 year history. How do they do you ask? I came across the secret formula on Emdashes. Simply select on item from each column and press-toe, you have yourself a funny.