function AddEngine(name,ext,cat) {
  if ((typeof window.sidebar == "object") && (typeof window.sidebar.addSearchEngine == "function"))
  {
    window.sidebar.addSearchEngine( 
		"http://www.naden.de/blog/wp-content/download/"+name+".src", 
		"http://www.naden.de/blog/wp-content/download/"+name+"."+ext,
		name,cat );
  }
  else
  {
    errorMsg(name,ext,cat);
  }
}

document.write( '<a href="javascript:AddEngine(\'ask_de\',\'gif\',\'ASK.de Suche\');">Installieren</a>' );