NAME
        CxCustom -- create a custom commodity object. (V36)

   SYNOPSIS
        customObj = CxCustom(action,id);

        cxobj *cxcustom(long(*)(),long);

   FUNCTION
        This function creates a custom commodity object. The action
        of this object on receiving a commodity message is to call a
        function of the application programmer's choice.

        The function provided ('action') will be passed a pointer to
        the actual commodities message (in commodities private data
        space), and will actually execute as part of the input handler
        system task. Among other things, the value of 'id' can be
        recovered from the message by using the function cxmsgid().

        The purpose of this function is two-fold. First, it allows
        programmers to create Commodities Exchange objects with
        functionality that was not imagined or chosen for inclusion
        by the designers. Secondly, this is the only way to act
        synchronously with Commodities.

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

   INPUTS
        action - a function to call whenever a message reaches the object
        id - a message id to assign to the object

   RESULTS
        customObj - a pointer to the new custom object, or NULL if it could
                    not be created.

  SEE ALSO
        commodities.library/createcxobj(), commodities.library/cxmsgid()