def section_save(section_key_us=None):
    form = SectionFormAdmin()

    # form validation
    if not form.validate_on_submit():
        return "VALIDATION_ERROR", 400

    # get and validate parent section
    if form.parent_section.data == '/':
        parent_section_key = None
    else:
        parent_section = ndb.Key(
            urlsafe=form.parent_section.data).get() or abort(404)
        parent_section_key = parent_section.key

    # section instance
    if section_key_us:
        # edit
        # print 'admin section save EDIT'
        section = ndb.Key(urlsafe=section_key_us).get() or abort(404)
    else:
        # new
        # print 'admin section save NEW'
        section = Section()

    # update data
    g.cache.clear()
    section.parent_section = parent_section_key
    section.set_name(form.name.data, g.language)
    section.put()
    return 'ok'