One of the most powerful features of PHP is the way it handles HTML
    forms. The basic concept that is important to understand is that any
    form element will automatically be available to your PHP 
    scripts.  Please read the manual section on
    Variables from outside 
    of PHP for more information and examples on using forms 
    with PHP.  Here is an example HTML form:
   
    
Example 2-6. A simple HTML form <form action="action.php" method="post">
 <p>Your name: <input type="text" name="name" /></p>
 <p>Your age: <input type="text" name="age" /></p>
 <p><input type="submit" /></p>
</form>  |  
  | 
   
    There is nothing special about this form. It is a straight HTML form
    with no special tags of any kind. When the user fills in this form
    and hits the submit button, the action.php page
    is called. In this file you would write something like this:
   
    
Example 2-7. Printing data from our form 
Hi <?php echo $_POST['name']; ?>. You are <?php echo $_POST['age']; ?> years old.
 |  
 
      A sample output of this script may be:
      Hi Joe. You are 22 years old.  |  
  | 
   
    It should be obvious what this does. There is nothing more to it.
    The $_POST['name'] and $_POST['age']
    variables are automatically set for you by PHP.  Earlier we
    used the $_SERVER autoglobal; above we just 
    introduced the $_POST
    autoglobal which contains all POST data.  Notice how the
    method of our form is POST.  If we used the 
    method GET then our form information would live in 
    the $_GET autoglobal instead.
    You may also use the $_REQUEST
    autoglobal, if you do not care about the source of your request data. It 
    contains the merged information of GET, POST and COOKIE data.  Also see the 
    import_request_variables() function.
   
    You can also deal with XForms input in PHP, although you will find yourself
    comfortable with the well supported HTML forms for quite some time.
    While working with XForms is not for beginners, you might be interested
    in them. We also have a short introduction
    to handling data received from XForms in our features section.