var win_ie_ver = parseFloat(navigator.appVersion.split("MSIE")[1]);
 if (win_ie_ver <= 8.0)
  {
  document.write('<link rel="stylesheet" type="text/css" href="includes/stylesheet.css">')
  }
  else
  {
  document.write('<link rel="stylesheet" type="text/css" href="includes/stylesheet2.css">')
  }