function FirefoxPlugin() {
  if ((typeof window.sidebar == "object") && (typeof window.sidebar.addSearchEngine == "function")){
    window.sidebar.addSearchEngine( "http://www.yourdomain.com/plugin/search.src",
                                    "http://www.yourdomain.com/images/bmark.gif",
                                    "yourdomain.com search",
                                    "yourdomain.com");
  }
}