;+
; NAME: setsky
; PURPOSE:
; 	Add offsets to images to make the background sky level equal
; 	to the background of the first image.
;
; INPUTS:
; KEYWORDS:
; 	/mean	subtract mean from each slice (old default)
; 			new default is to subtract the output of 'sky' for each.
;   smooth=	smooth this many pixels before computing sky values.
; OUTPUTS:
;
; HISTORY:
; 	Began 2005-11-14 15:36:18 by Marshall Perrin 
;-

PRO setsky,imgs,center=center,boxsize=boxsize,alsofix=alsofix,dsky=dsky, $
	mean=use_mean,all=all,smooth=smooth

	if ~(keyword_set(boxsize)) then boxsize=100
    if ~(keyword_set(center)) then begin
        findmaxstar,imgs[*,*,0],mx,my
    endif else begin
        mx=center[0]
        my=center[1]
    endelse

	if keyword_set(all) then imgs2=imgs else $
    imgs2 = imgs[mx-boxsize:mx+boxsize-1,my-boxsize:my+boxsize-1,*]

	if keyword_set(smooth) then imgs2 = smooth(imgs2,[smooth,smooth,1],/nan)

	if keyword_set(use_mean) then dsky = means(imgs2) else dsky = skys(imgs2)

	dsky -= mean(dsky) ; keep average sky level the same
	message,/info,"Found sky offsets:"
	print,dsky

	if total(finite(dsky)) ne n_elements(dsky) then message,"That box contains NaNs!"
	
	
	sz = size(imgs)
	for i=0L,sz[3]-1 do begin
		imgs[*,*,i] -= dsky[i]
	endfor 

	if arg_present(alsofix) then begin
		for i=1L,sz[3]-1 do begin
			alsofix[*,*,i] -= dsky[i]
		endfor 
	endif



end