Retrieving POST Data from AJAX Call to PHP

Can you see the ajax request data using the firebug console?

You cannot get the lastname, firstname from $_POST. It's inside the json string. First, you have to get the data using

 $data = $_POST['data'] or $_REQUEST['data']

Then, decode the $data using json_decode() and access your attributes.

json_decode($data);

$post = file_get_contents('php://input');