FUNCTION CreFn, wArr, nprefix, filprefix, nfid, fid
;	------------------------------------------------------------
;+						26-June-91
;	NAME:
;		CreFn
;	Purpose: 
;		Create a list of filenames.
;	CALLING SEQUENCE:
;		fnlist = CreFn( wArr, nprefix, filprefix, nfid, fid)
;	Input:
;		wArr	2-d list of selected file prefixes
;		nprefix	max number of file prefixes 
;		filprefix	list of valid prefixes
;		nfid	number of file ids
;		fid	list of file ids
;	Returned:
;		List of FileNames.	
;	History:
;		written 26-June-91 by GAL
;-
;	-----------------------------------------------------------
;	ON_ERROR, 2 	;force a return to caller on error

	fileNa = STRARR(1)	;fileName list dimensions
	tNa    = fileNa
	first = 1
	FOR i=0, nfid-1 DO BEGIN	;for each fid
	  FOR j=0, nprefix-1 DO BEGIN	;for each file prefix
	    row = WHERE(wArr(i,*) eq filprefix(j))
	    IF (row(0) ne -1) THEN BEGIN	;instrument j reqest
	      IF (first) THEN BEGIN		;start filename list
		fileNa(0) = filprefix(j) + fid(i)   
		first = 0		;set to false
	      ENDIF ELSE BEGIN		;append to list
		tNa(0) = filprefix(j) + fid(i)
		fileNa = [fileNa, tNa]
	      ENDELSE
	    ENDIF
	  ENDFOR
	ENDFOR
	fileNa = STRTRIM(fileNa, 2)	;trim 

	RETURN, fileNa
	END