http://mycroft.mozdev.org/deepdocs/browsertag.html#c27 i have made som search engine plugins too but the site ask me for tag, and i dont have any, if i put it alone it ask me for atributes Mozilla/5.0 (Windows; U; Windows NT 5.1; es-AR; rv:1.8.0.2) Gecko/20060308 Firefox/1.5.0.2