if (navigator && navigator.userAgent) {
  var css = $$('link[rel="stylesheet"]')[0];
  if (css && css.href) {
    var css_dir = css.href.substr(0,css.href.lastIndexOf('/'));
    if  (navigator.userAgent.match("MSIE 6")) {
      document.write('<link type="text/css" rel="stylesheet" href="'+css_dir+'/ie6.css" />\n');
    }
  }
}