FUNCTION jpl_inside, ET, SS

;+
; NAME:
;	jpl_inside
; PURPOSE:
;	Check whether time is inside current ephemeris file
; CATEGORY:
; CALLING SEQUENCE:
;	NR = jpl_inside(ET,SS)
; INPUTS:
;	ET(2)		double		ephemeris time
;	SS(2)		double		time range of ephemeris file
; OUTPUTS:
;	NR			integer 	record number in ephemeris file
;							with data for time ET.
;							NR=-1 if outside range.
; INCLUDE:
	@compile_opt.pro		; On error, return to caller
; PROCEDURE:
; MODIFICATION HISTORY:
;	FEB-2005, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;-

CASE SS[0] LE ET[0]+ET[1] AND ET[0]+ET[1] LE SS[1] OF
0: NR = -1L
1: NR = long((ET[0]-SS[0])/SS[2])-long(ET[0] EQ SS[1])
ENDCASE

RETURN, NR  &  END