h_id	IN:	Access identifier returned by Hstartread, Hstartwrite, or Hnextread
	file_id	OUT:	File identifier returned by Hopen
	tag	OUT:	Tag of the element pointed to
	ref	OUT:	Reference number of the element pointed to
	length	OUT:	Length of the element pointed to
	offset	OUT:	Offset of the element in the file
	position	OUT:	Current position within the data element
	access	OUT:	The access type for this data element
	special	OUT:	Special code

	Purpose	Returns access information about a data element.
	Return value	Returns SUCCEED (or 0) if the access identifier points to a valid data element and FAIL (or -1) otherwise.
	Description	If h_id is a valid access identifier the access type (read or write) is set regardless of whether or not the return value is FAIL (or -1). If h_id is invalid, the function returns FAIL (or -1) and the access type is set to zero. To avoid excess information, pass NULL for any unnecessary pointer.