var currentLoc = window.location;
var currentTitle = document.title;

function bookmarksite(){
    if (window.sidebar) // firefox
        window.sidebar.addPanel(currentTitle, currentLoc, "");

    else if(window.opera && window.print){ // opera
        var elem = document.createElement('a');
            elem.setAttribute('href',currentLoc);
            elem.setAttribute('title',currentTitle);
            elem.setAttribute('rel','sidebar');
            elem.click();
        }

    else if(document.all)// ie
        window.external.AddFavorite(currentLoc, currentTitle);
    }