js判断IE浏览器版本，如果版本过低则直接跳转到升级页面
<script>/*@cc_on var temp = window.navigator.userAgent.toUpperCase();var charHead = temp.indexOf('MSIE');var charLast = temp.indexOf(";", charHead);var ieVersion = temp.substring(charHead, charLast);ieVersion = ieVersion.split(' ')[1];if (ieVersion <= 8) {window.location.href="/upgrade-your-browser.html?referrer="+encodeURIComponent(window.location.href);} @*/</script>
