Bookmark IE and firefox

Bookmark which works in Firefox and internet explorer.

Example
(html in 'a' tag)
href=javascript:addBookmark("http://www.dartcalculators.com","Dartcalculators%20-%20Free%20to%20use%20dart%20calculators") title="Bookmark www.dartcalculators.com">

(javascript)
function addBookmark(url,desc){
var bookmarkurl = url;
var bookmarktitle = desc;
var nonie = 'Sorry, only Mozilla Firefox and Internet Explorer support this method to add a bookmark/favourite\n But please feel free to visit the site\'s home page to add a bookmark manually';

if (window.sidebar) { // Mozilla Firefox Bookmark
window.sidebar.addPanel(bookmarktitle, bookmarkurl,"");
} else if(document.all){ // IE Favourites
window.external.AddFavorite(bookmarkurl,bookmarktitle);
} else {
alert(nonie);
}
}