分离IE9以下浏览器

/*判断浏览器版本是否过低*/
        function IETester(userAgent) {
            var UA = userAgent || navigator.userAgent;
            if (/msie/i.test(UA)) {
                return UA.match(/msie (\d+\.\d+)/i)[1];
            } else if (~UA.toLowerCase().indexOf('trident') && ~UA.indexOf('rv')) {
                return UA.match(/rv:(\d+\.\d+)/)[1];
            }
            return false;
        }

        //console.log(IETester());//不传参数返回当前IE版本，如果不是IE内核浏览器，返回false
        if (IETester() == 9.0) {
            //$(".hearder .right").css({"position": "absolute", "z-index": "-1"});
        } else if (IETester() == 8.0 || IETester() == 7.0 || IETester() == 6.0 || IETester() == 5.0) {
            window.location.href = 'iepoint/index.html';
        }