xampp - Undefined Index for $_POST (noob question!)

I
am just learning PHP and I keep getting an Undefined Index error. The book I'm learning
from has an HTML form and a PHP page that processes the form, using the following
format:

            name="howlong" />

// The PHP starts with one line like this for
            each of the form fields in the HTML
$how_long = $_POST
            ['howlong'];


// And there is one line for each one like
            this to output the form data: 
echo ' and were gone for ' . $how_long .
            '
';

The
example I'm working with has about 12 form
fields.

What's odd is that not all of the
variables throw this error, but I can't see a pattern to
it.

I've checked that all HTML fieldnames match
up with the PHP $_POST variable name I entered, and I've made certain that when I fill
out the form and submit it that all fields are filled in with something. Interestingly,
the completed code that can be downloaded for the book also throws this
error.

I realize this code may not
reflect best practices, it's from the first chapter of the book and obviously I am a
noob :)

In case it makes a difference, I am
using PHP 5.3.5 on XAMPP 1.7.4 with Windows 7 Home Premium.

Answer

Remember to set the method to POST on the
form tag...

heres the code i used to try yours,
and it worked to me:

in a file named
test.php:

            
 


            
             type="submit" value="submit"/>
 

            

and
in
testProc.php:

if
            (isset($_POST)) {
 if (isset($_POST["howlong"])){
 $howlong =
            $_POST['howlong'];
 echo ' and were gone for ' . $howlong . '            />';

            }
}

?>

Just
as an advise, to make display manipulation with stylesheets i recommend to put forms
within a table, like
this:

            
 


            














 
 
            

 How long? :

            
 

             name="howlong" />
 
 
            
             
 
 

            

            

Hope
you can use this...