function bookmark(){

var IE = navigator.appName.match(/(Microsoft Internet Explorer)/gi),
    NS = navigator.appName.match(/(Netscape)/gi),
    OP = navigator.appName.match(/(Opera)/gi)

    if(IE && document.uniqueID){window.external.AddFavorite(location.href,document.title);

    }

    else if(OP || IE && !document.uniqueID){alert('Your browser requires that you\nPress Ctrl & T to Bookmark this page.');

     }

    else if(NS){alert('Your browser requires that you\nPress Ctrl & D to Bookmark this page.');

     }

    else {alert('Your browser does support the\nautomatic bookmarking feature.');
    }
}