[Resolvido] erro - envia email vazio

Boas, eu não percebo nada de ajax, como tal nao consigo dar com o erro:

o codigo:

...

var dataString = '?' + 'firstname=' + firstname + '&lastname=' + lastname +'&email=' + email + '&subject=' + subject + '&message=' + message;
 //alert (dataString);return false;

 $.ajax({
 type: "POST",
 url: "<?php bloginfo('template_url'); ?>/library/inc/process.php",
 data: dataString,
 success: function() {

 $('#contact-form').slideUp("fast", function() {
 $(this).before('<div id="contact-form"><h3><?php _e('<strong>Thanks!</strong><br> Your email was successfully sent. I check my email all the time, so I should be in touch soon.', 'wf') ?></h3></div>');
 });
 return false;
 }
 });
...

eu descomento o alerta() e os dados estam ok...

volto a comentar, corro o scrip e ele processa um email vazio...

...

$firstname = trim($_GET['firstname']);
$lastname = trim($_GET['lastname']);
$name = $firstname.' '.$lastname;
$email = trim($_GET['email']);
$subject = trim($_GET['subject']);
$message = trim($_GET['message']);

$emailTo = 'qualquer@gmail.com';
$body = "Name: $name \n\nEmail: $email \n\nMessage: $message";
$headers = 'From: vitorteixeira.co.cc <' . $emailTo . '>' . "\r\n" . 'Reply-To: ' . $email;

mail($emailTo, $subject, $body, $headers);

...

se me poderem ajudar fico grato...

fiquem bem