The program asks the user to enter some values into an HTML form, and then uses those values to build a custom version of a classic nursery rhyme. The story program works like most server-side programs. It has two distinctive parts. First, the user enters information into a plain HTML form and hits the submit button. The PHP program doesn't execute until after the user has submitted a form. The program takes the information from the form and does something to it. Usually the PHP program also returns an HTML page to the user.