function bookmarkus()
 {
 	if ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4))
 	{
 		var url="http://www.bookhead.co.uk";
 		var title="Bookhead.co.uk. Saving on books by comparison";
 		window.external.AddFavorite(url,title);
 	}
 }