def markfilename(filename,creatorcode=None,filetype=None,ext='PDF'):
        try:
            if creatorcode is None or filetype is None and ext is not None:
                try:
                    creatorcode, filetype = _KNOWN_MAC_EXT[ext.upper()]
                except:
                    return
            macfs.FSSpec(filename).SetCreatorType(creatorcode,filetype)
            macostools.touched(filename)
        except:
            pass