function IEVersion() {            var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串              var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1; //判断是否IE<11浏览器              var isEdge = userAgent.indexOf("Edge") > -1 && !isIE; //判断是否IE的Edge浏览器              var isIE11 = userAgent.indexOf('Trident') > -1 && userAgent.indexOf("rv:11.0") > -1;            if (isIE) {                var reIE = new RegExp("MSIE (\\d+\\.\\d+);");                reIE.test(userAgent);                var fIEVersion = parseFloat(RegExp["$1"]);                if (fIEVersion == 7) {                    return 7;                } else if (fIEVersion == 8) {                    return 8;                } else if (fIEVersion == 9) {                    return 9;                } else if (fIEVersion == 10) {                    return 10;                } else {                    return 6;//IE版本<=7                }            } else if (isEdge) {                return 'edge';//edge            } else if (isIE11) {                return 11; //IE11              } else {                return -1;//不是ie浏览器            }        };