def get(self):
     if not self.is_logged_in():
         self.redirect(LOGIN_PAGE_URL)
     else:
         from models import SubscriptionPeriod
         products = Product.get_all()
         subscription_periods = SubscriptionPeriod.get_all()
         self.render('select_products.html',
             products=products,
             subscription_periods=subscription_periods)