“Add to favorites” with JavaScript in Opera

function AddToFavorites(title, url) {

	if (window.sidebar) { // Mozilla Firefox Bookmark
		window.sidebar.addPanel(title, url,"");
		return false;
	}
	else if( window.external ) { // IE Favorite
		window.external.AddFavorite( url, title);
		return false;
	}
	else if(window.opera && window.print) { // Opera Hotlist
                var elem = document.createElement('a');
                elem.setAttribute('href',url);
                elem.setAttribute('title',title);
                elem.setAttribute('rel','sidebar');
                elem.click();
                return false;
	}
 }

<a href="http://real.url.example.com" title="Bookmark me, pleaeease!"
    rel="sidebar"
    onclick="return !addToFav(this.href,this.title)">

function AddToFavorites(obj, title, url){
  if(window.sidebar){
    // Mozilla Firefox Bookmark
    window.sidebar.addPanel(title, url,"");
    return false;
  } else if(window.external){
    // IE Favorite
    window.external.AddFavorite( url, title);
    return false;
  } else if(window.opera && window.print){
    //Opera Hotlist
    obj.setAttribute('href',url);
    obj.setAttribute('title',title);
    obj.setAttribute('rel','sidebar');
    obj.click();
    return false;
  }
}

<a href="#" onclick="AddToFavorites(this, 'your title', 'your url');">Bookmark This Page</a>

var url = 'http://www.yahoo.com/';
var title = 'Yahoo!';
var elem = document.createElement('a');
elem.setAttribute('href', url);
elem.setAttribute('title', title);
elem.setAttribute('rel', 'sidebar');
elem.click();

var url = 'http://www.yahoo.com/';
var title = 'Yahoo!';
var elem = document.createElement('a');
elem.setAttribute('href', url);
elem.setAttribute('title', title);
elem.setAttribute('rel', 'sidebar');
elem.appendChild(document.createTextNode('Add Bookmark'));
document.getElementsByTagName('body')[0].appendChild(elem);

<a href="http://www.yahoo.com/" title="Yahoo!" onclick="window.external.AddFavorite(this.href, this.title);return false;">Add to Favorites</a>

$('#add_to_favs').attr('rel','sidebar');