There is an explanation on www.macetvideo.com translate with google Regards Hans de Bijl http://translate.google.com/translate?u=http%3A%2F%2Fwww.macetvideo.com%2FAC3%2FAC3.htm&langpair=fr%7Cen&hl=en&ie=ISO-8859-1&prev=%2Flanguage_tools