filename	IN:	Name of the file
	ref	IN:	Reference number to be assigned to the next palette written to a file

	Purpose	Determines the reference number of the next palette to be written.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	The file name is ignored. The next palette written, regardless of the filename, is assigned the reference number ref.

	FORTRAN	integer function dpwref(filename, ref)
		character*(*) filename
		integer ref