Ajax load

<!-- button -->
<button onclick="load();">Click</button>

<!-- box -->
<div id="redactor-box"></div>

<!-- load -->
<script>
function load()
{
    var request = new XMLHttpRequest();
    request.open('GET', 'redactor.html', true);
    request.onload = function()
    {
        if (request.status >= 200 && request.status < 400)
        {
            var box = document.getElementById('redactor-box');
            box.innerHTML = request.responseText;

            // call
            $R('#content', { focus: true });
        }

    };
    request.send();
}
</script>

<!-- redactor.html -->
<textarea id="content">...</textarea>
<!-- / redactor.html -->