// 翻转替换里面所有的html代码的尖括弧   function replaceRevertAllHTML(txt){    var value  =  txt    var leftCarr = /</g ;    var rightCarr =/>/g ;    var dan = /'/g;    var and = /&/g;    var sh

function getOs() {             if (isFirefox = navigator.userAgent.indexOf("Firefox") > 0) {                 return "Firefox";             }             alert(22222);             if (navigator.us