Manipulating variables that you set within your script is somewhat interesting, but hardly anything to rave about. Scripts become much more useful when they use input from the user. When you call PHP from an HTML form, the form fields are turned into variables. Listing 1.4 is a form that calls Listing 1.5, a further modification of our example script.
Listing 1.4 is a standard HTML form. If you have dealt at all with CGIs, it will look familiar. There are three form fields that match up with the variables from our previous example. Instead of simply putting data into the variables, ...