Can't process simple form submitted by jQuery ajax

My form:

<form id="new-protocol-form" method="post" role="form">
  <textarea name="text"></textarea>
</form>

---

My jquery ajax:

$('#submitProtocol').click(
    function() {
        $.ajax({
            type:    "POST",
            url:     "newProtocol.php",
            data:    $('#new-protocol-form').serialize(),
            success: function() { alert{'ok'} },
            error:   function() { alert('error'); }
        });
    }
);

---

My newProtocol.php:

<script>
    alert(<?php $_POST('text'); ?>);
</script>

---

Alert window with 'ok' text triggered by ajax 'success' method is shown, but I can't get alert window with $_POST['text'] value from newProtocol.php file. No error in javascript console.