[jQuery] Ajax get contents question

[jQuery] Ajax get contents question


This is my testing php code, I found if I use filter, I can only get
the content from first level of object, for example
<div id="res">1<div id="res2">2</div></div>
I can get res's contents by filter, but I can't get res2's contents,
is that possible that get any thing I want through ajax?
<?php
if (isset($_POST['g'])) {
    echo '<div id="res">1<div id="res2">2</div></div>';
    exit;
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://
www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>get</title>
<script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
</head>
<body>
<div id="show"></div>
<input type="button" id="btn1" value="btn1" />
<input type="button" id="btn2" value="btn2" />
<script>
$(function() {
    $('#btn1').click(function() {
        $.post('get.php', {g: 1}, function(data) {
            var data = $(data).filter('#res').html();
            $('#show').html(data);
        });
    });
    $('#btn2').click(function() {
        $.post('get.php', {g: 1}, function(data) {
            var data = $(data).filter('#res2').html();
            $('#show').html(data);
        });
    });
});
</script>
</body>
</html>