Browser Bookmark

function addBookmark() {
  if(document.all) //MSIE
    window.external.AddFavorite(document.location.href,document.title);
  else if (window.sidebar)
    window.sidebar.addPanel(document.title, document.location.href,"");
  else
    alert('Close this popup and press Ctrl-D to bookmark this page');
}

This is a cross-browser function to perform Add Bookmark using javascript.
Working example: Add to Favorites