def save(nsc, site_id)
      validate
      uri = "/api/2.1/site_configurations/#{site_id}/alerts"
      id  = AJAX.put(nsc, uri, self.to_json, AJAX::CONTENT_TYPE::JSON)
      @id = id.to_i
    end
def save(nsc, site_id)
      validate
      uri = "/api/2.1/site_configurations/#{site_id}/alerts"
      id  = AJAX.put(nsc, uri, self.to_json, AJAX::CONTENT_TYPE::JSON)
      @id = id.to_i
    end
save an alert for a given site