status.i4.v = ntv_check_reply(request_id.u2.r [,return_length.u2.r]
				      [,reply_flags.i1.r] [,status.i2.r])

	Check on the arrival of a reply to an outstanding request.
	This routine returns immediately with NET__PENDING (0) if
	no reply has yet arrived.

	request_id	word containing the request identification code for
			the request for which the arrival of a reply is
			being checked.

	[return_length]	word in which the length of the reply message (if any)
			is returned (length is in words).

	[reply_flags]	byte in which the reply flags of the reply message
			(if any) are returned.  This is a structure of type
			(UAB_M_MULTRPY -> multiple-reply message type,
			 UAB_M_TOOLONG -> message is too long for buffer,
			 UAB_M_1STPKT  -> set when first (in time) packet
					  of the reply message has been
					  stored in the reply buffer)

	[status]	word in which the ACNET global reply status of the
			reply (if any) is returned.

	status	 VMS completion condition code or NET__PENDING.

	The values returned in the arguments have meaning only if
	the completion code is not NET__PENDING.

	This function returns status values as follows:

	NET__PENDING	reply has not yet arrived (value of code is 0).
	SS__NORMAL	success, reply received
	SS__ACCVIO	address of a request id word not provided
	SS__ILLEFC	illegal event flag number
	SS__INSFARG	insufficient number of arguments
	SS__UNASEFC	process not associated with event flag cluster with
			the specified event flag number
	NET__NOSUCHREQ	no such request as given by request id
	NET__NOTBLKOWN	not owner of the reply control block
	NET__NOTCNCT	not connected.
	NET__NOTREQID	not a request identification code

	These are the 32-bit condition codes returned from translating
	the reply status code in the message header:

	SS__NORMAL	success
	NET__ENDMLTRPY	success, final reply in a set of multiple replies
	SS__BADPARAM	bad value in ACNET typecode block
	SS__COMMHARD	hard communications I/O error
	SS__MSGNOTFND	unknown reply status presented
	SS__NOSUCHNODE	no such logical node
	SS__NOSUCHOBJ	no such task at destination node
	SS__TIMEOUT	request timed-out while queued for locked
			receive buffer
	NET__DISCONING	replier task being disconnected
	NET__ILLACNCOD	illegal or unknown ACNET request typecode or
			sub-function value
	NET__INCWRTPWD	incorrect ACNET WRITE function password
	NET__IOERROR	retryable I/O error
	NET__NODEDOWN	destination logical node down
	NET__NOMEMRMT	no memory available at remote node
	NET__NOSUCHREQ	no such request
	NET__REQPKTERR	request message packet assembly error
	NET__REQTRUNC	request message truncated
	NET__RPYPKTERR	reply message packet assembly err
	NET__RPYTBLFUL	request failed, no room in reply tables
	NET__RPYTRUNC	reply message truncated
	NET__SYSERR	system service or directive error
	NET__TASKBUSY	request failed, destination task busy
	NET__TSKQFUL	request failed, receive buffer queue full

	This function requires the following include files:

	acnet_h, ssdef_h

	Related functions:

	ntv_wait_reply, net_rpysts_test