def redirect_to_login(next, redirect_field_name=REDIRECT_FIELD_NAME):
    """
    Redirects the user to the login page, passing the given 'next' page
    """
    resolved_url = reverse('IS:login')

    login_url_parts = list(urlparse(resolved_url))
    if redirect_field_name:
        querystring = QueryDict(login_url_parts[4], mutable=True)
        querystring[redirect_field_name] = next
        login_url_parts[4] = querystring.urlencode(safe='/')

    raise HTTPRedirectResponseException(urlunparse(login_url_parts))