Não entendo porquê....
Experimenta este:
dentro das tags <head> e </head>:
<script type="text/javascript">
/***********************************************
* Bookmark site script- © Dynamic Drive DHTML code library (www.dynamicdrive.com)
* This notice MUST stay intact for legal use
* Visit Dynamic Drive at http://www.dynamicdrive.com/ for full source code
***********************************************/
function bookmarksite(title, url){
if (document.all)
window.external.AddFavorite(url, title);
else if (window.sidebar)
window.sidebar.addPanel(title, url, "")
}
</script>
no body:
<a href="javascript:bookmarksite('Dynamic Drive', 'http://www.dynamicdrive.com')">Bookmark this site!</a>