FUNCTION SORT_LE,headls,field,filter=filter,exptime1=exptime1,exptime2=exptime2

 IF headls(0) EQ '' THEN RETURN,headls

 IF KEYWORD_SET(filter) THEN BEGIN

   f = STR_SEP( filter, ' ')
   i = WHERE( f GT '')
   ni = n_elements(i)
   tmp = f(i(0))

   for j=1,ni-1 do tmp = tmp + " " + f(i(j))
   filter = tmp
   
   tmp = ''
   n = n_elements(headls)

   IF n EQ 0 THEN RETURN," "
   sorted = STRARR(n)
   for i=0,n-1 do begin
      line = headls(i)
;print,line
      tmp = STR_SEP(line,' ')
      ii = WHERE(tmp GT '')
      sorted(i) = tmp(ii(field))
      if ni eq 2 then sorted(i) = sorted(i) + " " + tmp(ii(field+1))
      if STRMID(sorted(i),0,1) EQ 'X' then sorted(i) = tmp(ii(field+1)) 
   endfor

   ind = WHERE(sorted EQ filter)
   tmp = ''
   IF ind(0) GT -1 THEN tmp = headls(ind)
               
   tmps = tmp

 ENDIF

 IF KEYWORD_SET(exptime1) THEN BEGIN

   time1 = exptime1 < exptime2
   time2 = exptime1 > exptime2

   tmp = ''
   n = n_elements(headls)
   IF n EQ 0 THEN RETURN," "
   sorted = FLTARR(n)
   for i=0,n-1 do begin
      line = headls(i)
      tmp = STR_SEP(line,' ')
      ii = WHERE(tmp GT '')
      sorted(i) = FLOAT(tmp(ii(field)))
   endfor
   ind = WHERE(sorted  GE time1 AND  sorted LE time2)
   tmp = ''
   IF ind(0) GT -1 THEN  tmp = headls(ind)
               
   tmps = tmp


 ENDIF

RETURN,tmps
END