PHP form - on submit stay on same page

Question

I have a PHP form that is located on file contact.html.

The form is processed from file processForm.php.

When a user fills out the

Answer 1

What I do is I want the page to stay after submit when there are errors...So I want the page to be reloaded :

($_SERVER["PHP_SELF"])

While I include the sript from a seperate file e.g

include_once "test.php";

I also read somewhere that

if(isset($_POST['submit']))

Is a beginners old fasion way of posting a form, and

if ($_SERVER['REQUEST_METHOD'] == 'POST')

Should be used (Not my words, read it somewhere)