Update TinyMCE with json

HTML

<script src="http://www.tinymce.com/js/tinymce/jscripts/tiny_mce/tiny_mce_jquery.js"></script>
<button id="calljson">Call conente from server</button>
<hr />
<textarea id="content" name="content">
    <p>Old text</p>
</textarea>

CSS

a {
    pointer: default;
}

JavaScript

tinyMCE.init({
    mode: "textarea"
});

$(function() {

    $("#calljson").bind("click", function() {
        var ed = tinyMCE.get('content');
        ed.setProgressState(1); // Show progress
        $.ajax({
            url: '/echo/json/',
            delay: 4,
            data: {
                json: "{'content': '<h1>New header</h1><p>new content</p>'}"
            },
            dataType: 'json',
            success: function(data) {
                ed.setProgressState(0); // Hide progress
                ed.setContent(data.content);

            },
            error: function() {
                alert("error");
            }
        });
    });
});