// my message structs


struct netmsg
{
int type;
};

struct netmsg_position : public netmsg
{
	int x,y;
};

// message types


enum messagetype { msgtype_position = 0, msgtype_message = 1 };

// function that send a message


void myengine::net::client::send(netmsg msg,int msgsize)
{
	if(m_connected)
	{
		DPNHANDLE handle;

		// description

		DPN_BUFFER_DESC desc;
		desc.dwBufferSize = msgsize;
		desc.pBufferData = (BYTE*)&msg

		// send

		m_dpclient->Send(&desc,1,0,NULL,NULL,DPNSEND_SYNC | 
			DPNSEND_GUARANTEED | DPNSEND_NOCOPY | DPNSEND_NOLOOPBACK);
	}
}

// send a message


netmsg_position pos;
pos.type = msgtype_position;
pos.x = 23;
pos.y = 19;

m_client->send(msg,sizeof(netmsg_message));

// inside message handler for server


case DPN_MSGID_RECEIVE:
	// message received

	PDPNMSG_RECEIVE data = (PDPNMSG_RECEIVE)msg_buffer;
	netmsg *msg = (netmsg*)data->pReceiveData;
	((server*)user_context)->on_client_receive(msg->type,data->pReceiveData);
	return S_OK;

// function that handles message


void myengine::net::server::on_client_receive(int msgtype,PBYTE msg)
{
if(msgtype == msgtype_position)
{ 
	netmsg_position *pos = (netmsg_position*)msg;
	dosomething(pos);
}
else if(msgtype == msgtype_message)
{
	netmsg_message *mess = (netmsg_message*)msg;
	dosomething(mess);
}
}