function detectIE6(){
  var browser = navigator.appName;
  if (browser == "Microsoft Internet Explorer"){
    var b_version = navigator.appVersion;
    var re = /\MSIE\s+(\d\.\d\b)/;
    var res = b_version.match(re);
    if (res[1] <= 6){
      document.getElementById('forie').style.display = 'block';
    }
  }
  return false;
}