code: public String sendMessage(String gatewayId, Struct data) throws PageException, IOException {
  	Gateway g = getGateway(gatewayId);
  	if (g.getState() != Gateway.RUNNING) throw new GatewayException("Gateway [" + gatewayId + "] is not running");
  	return g.sendMessage(data);
      }
docs: send the message to the gateway
  
  @param gatewayId
  @param data
  @return
  @throws PageException