ri_id	IN:	Raster image identifier returned by GRcreate or GRselect
	interlace_mode	IN:	Interlace mode

	Purpose	Specifies the interlace mode to be used in the subsequent raster image read operation(s).
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	GRreqimageil requests that the subsequent read operations on the image identified by the parameter ri_id use the interlace mode specified by the parameter interlace_mode.
		The parameter interlace_mode specifies the interlace mode in which the data will be stored in memory when being read. Valid values of the parameter interlace_mode are MFGR_INTERLACE_PIXEL (or 0), MFGR_INTERLACE_LINE (or 1) and MFGR_INTERLACE_COMPONENT (or 2).
		In the file, the image is always stored in pixel interlace mode, i.e. MFGR_INTERLACE_PIXEL. The interlace mode of the raster image specified at creation time is stored in the file along with the raster image. If GRreqimageil is not called prior to the call to GRreadimage, the raster image will be read and stored in memory according to the interlace mode specified at creation. If GRreqimageil is called before GRreadimage, GRreadimage will read the raster image and store it according to the interlace mode specified in the call to GRreqimageil.

	FORTRAN	integer function mgrimil(ri_id, interlace_mode)
		integer ri_id, interlace_mode