def index(req, res):
    """
    Return root page of website.
    """
    number = req.session.get('counter', -1)
    req.session['counter'] = int(number) + 1
    print(" -- Session '{id}' returned {counter} times".format(**req.session))
    msg = "Hello!! You've been here [[%s]] times" % (req.session['counter'])
    res.send_text(msg)
    req.session.save()
Return root page of website.