http://livehttpheaders.mozdev.org/suggestions.html#c389 Soory, the last message for a better syntax : fenyx.fr/firefox/livehttpheaders-0.13.2-beta-fx.xpi Bye Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1