HTML forms are one of the key ingredients of any dynamic website because they can enable the users of a site to interact with it. Otherwise, websites are more or less static: They may be driven by a database and, therefore, regularly changing, but they look the same for each and every visitor. HTML forms can change that; therefore, using data from forms from within PHP is very important.
Reading the information in is a very easy task: For form data submitted via
GET (that is, in the Uniform Resource Identifer [URI] of the page requested), the data can be found in
$_GET[<value of name attribute of form field>]. However, this is only the beginning. Suppose a user fills out a form but forgets one field. Instead ...