function addEngine() {
    if ((typeof window.sidebar == "object") && (typeof window.sidebar.addSearchEngine == "function")) { 
        window.sidebar.addSearchEngine(
            "http://www.noseque.net/wordpress/media/archivos/googleadsfree.src",
            "http://www.noseque.net/wordpress/media/imagenes/googleadsfree."+'png', 'A9', ''
        );
    } else {
        alert("Sorry, you need a Mozilla-based browser (such as Firefox) to install a search plugin.");
    } 
}