FUNCTION getwid, prefix, dir
;   ----------------------------------------------------------------
;   --------------------------------------------------------------

    cd, '', current=olddir          ;save old dir

    cd, dir
    fns = findfile(prefix+'*')      ;get files names

    IF fns(0) ne '' then begin
      len = MAX(strlen(fns))
      ids = strmid(fns, 3, len-3)

      tim2orbit, (fid2ex(ids)), wid=wids    ;get the wids

      wids = wids(uniq(wids, sort(wids)))   ;just list of unique
    ENDIF ELSE BEGIN
      wids = ''
    ENDELSE

    cd, olddir              ;return to original dir

    return, wids

    end