ajax.autosave.versioning.html

<form method="POST" action="/our/url">
    <!-- this should have the current value of version_number -->
    <input type="hidden" name="version_number" value="1" />
    <textarea name="input" onChange="save(event)" />
</form>


function save(event) {
    event.target.form['version_number'].value++;
    var request = new XMLHttpRequest();
    request.open(event.target.form.method, event.target.form.action);
    request.send(new FormData(event.target.form));
}