function getBrowserInfo() {
  var t,v = undefined;
  if (window.opera) 
    t = 'Opera';
  else if (document.all) 
  {
    t = 'IE';
    var nv = navigator.appVersion;
    var s = nv.indexOf('MSIE')+5;
    v = nv.substring(s,s+1);
  }
  else 
    if (navigator.appName) t = 'Netscape';

  return {type:t,version:v};
}
 
function bookmark(a)
{
  var url = window.document.location;
  var title = window.document.title;

  var b = getBrowserInfo();
  if (b.type == 'IE' && 7 > b.version && b.version >= 4) {
    window.external.AddFavorite(url,title);
  }
  else if (b.type == 'Opera') {
    a.href = url;
    a.rel = "sidebar";
    a.title = url+','+title;
    return true;
  }
  else if (b.type == "Netscape") { 
    window.sidebar.addPanel(title, url, '');
  } else {
    alert("Нажмите CTRL-D, чтобы добавить страницу в закладки.");
  }
}