Given that PHPs primary role is handling web pages, you might wonder why this section has been left so late in the chapter. It is because handling HTML forms is so central to PHP that it is essentially automatic.
Consider this form:
<form method="POST" action="thispage.php">User ID: <input type="text" name="UserID" /><br />Password: <input type="password" name="Password" /><br /><input type="submit" /></form>
When a visitor clicks Submit,
thispage.php is called again, and this time PHP has the variables available to it inside the
$_REQUEST array. Given that script, if the user enters
frosties as her user ID and password, PHP provides you with
$_REQUEST['UserID'] set to