NAME
        CxSender -- create a commodity sender object. (V36)

   SYNOPSIS
        senderObj = CxSender(port,id)

        cxobj *cxsender(struct msgport *,long);

   FUNCTION
        This function creates a Commodities sender object. The action
        of this object on receiving a Commodities message is to copy the
        Commodities message into a standard Exec message, to put the value
        'id' in the message as well, and to send the message off to the
        message port 'port'.

        The value 'id' is used so that an application can monitor
        messages from several senders at a single port. It can be retrieved
        from the Exec message by using the function cxmsgid(). the value can
        be a simple integer ID, or a pointer to some application data
        structure.

        Note that Exec messages sent by sender objects arrive
        asynchronously at the destination port. Do not assume anything about
        the status of the Commodities message which was copied into the Exec
        message you received.

        All Exec messages sent to your ports must be replied. Messages may be
        replied after the sender object has been deleted.

        This function is a C-language macro for createcxobj(), defined
        in <libraries/commodities.h>.

   INPUTS
        port - the port for the sender to send messages to
        id - the id of the messages sent by the sender

   RESULTS
        senderObj - a pointer to the sender object, or NULL if it could
                    not be created.

   SEE ALSO
        commodities.library/createcxobj(), commodities.library/cxmsgid(),
        exec.library/putmsg(), exec.library/replymsg()