How do I redirect a page in PHP After User Submission?

Ok first, thing, get rid of the $_SERVER['REQUEST_METHOD'].  Right now if a form is set to post at your address it will be processed.  Spam bots love these forms because you are not actually checking if your own form was submitted.  You should usually only need to check if $_POST['something'] is submitted.  I know I didn't say this before but I should have.

Next, move the <?php ?> to the beginning of the document before the <!DOCTYPE declaration.

Now, eliminate the "else" statement.

Next eliminate the "echo Thank you" line and the $_POST = array(); line.  $_POST is a superglobal and always an array so you should never have to define it. And if you are redirecting someone, there is nothing you need to echo.

So now your code should be down to:

<?php if ( isset($_POST['submit']) && !empty($_POST['submit')) //Test if submit button named submit was clicked and not empty {           if (!empty($_POST['first']) && !empty($_POST['last'])  && !empty($_POST['email'])) {                     $body = "First Name: {$_POST['first']}\nLast Name: {$_POST['last']}\nEMail Address: {$_POST['email']}\nContact Phone Number: {$_POST['phone']}\nContact Preference: {$_POST['contactvia']}\nBest Time To Contact: {$_POST['timepref']}\nComments:\n {$_POST['comment']}";                     $body = wordwrap($body, 70);                     mail('someone@someplace.net', 'NEW Customer Inquiry Submission',$body, "From: {$_POST['email']}");                     header('Location: url.php');  //Redirect to new url if form submitted      } } ?> <!DOCTYPE

Just move that "Please fill out the form" text to the actual page above the form.  Then if the user submitted the form, they will get redirected, if not they see the page.  Make sense?