function addEngine(name,ext,cat,pid)
{
  if ((typeof window.sidebar == "object") && (typeof window.sidebar.addSearchEngine == "function")) {
    window.sidebar.addSearchEngine(
      "http://mycroft.mozdev.org/install.php/" + pid + "/" + name + ".src",
      "http://mycroft.mozdev.org/install.php/" + pid + "/" + name + "."+ ext, name, cat );
  } else {
    alert("You will need a browser which supports Sherlock to install this plugin.");
  }
}