jquery how to get the status message returned by a ajax call of type post?

javascript

    $('#send').on('click', function() {
        $.ajax({
            'url': $('#url').val(),
            'type': 'post',
            'complete': function (jqXHR, textStatus) {
                var msg = "Status: " + jqXHR.status + " (" + jqXHR.statusText + " - " + textStatus + ")<br />";
                msg += jqXHR.getAllResponseHeaders().replace(/\n/g, "<br />");

                $('#results').html(msg);
            }
        });
    });

php

    header("HTTP/1.0 200 Some message here");
    flush();
    exit();

Results

Status: 200 (OK - success)
Date: Wed, 07 Dec 2011 21:57:50 GMT 
X-Powered-By: PHP/5.3.6 
Transfer-Encoding: chunked 
Connection: Keep-Alive 
Server: Apache/2.2.17 (Unix) mod_ssl/2.2.17 OpenSSL/0.9.8r DAV/2 PHP/5.3.6 
Content-Type: text/html 
Keep-Alive: timeout=5, max=100 

Question

How do I get the "Some message here" part of the header?

http

http protocol

6.1 Status-Line

The first line of a Response message is the Status-Line, consisting of the protocol version followed by a numeric status code and its associated textual phrase, with each element separated by SP characters. No CR or LF is allowed except in the final CRLF sequence.

   Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF