JS判断IE版本

　　  var browser = navigator.appName;
        var b_version = navigator.appVersion;

        if (browser == "Microsoft Internet Explorer") {
            if (b_version.toString().indexOf("IE10") > 0 || b_version.toString().indexOf("IE 10") > 0) {
                for (var i = 0; i < c1; i++) {
                    strtableleftTd.childNodes[0].childNodes[i].style.borderCollapse = "collapse";
                }
            }
            else if (b_version.toString().indexOf("IE9") > 0 || b_version.toString().indexOf("IE 9") > 0) {
                for (var i = 0; i < c1; i++) {
                    strtableleftTd.childNodes[0].childNodes[i].style.borderCollapse = "collapse";
                }
            }
            else if (b_version.toString().indexOf("IE8") > 0 || b_version.toString().indexOf("IE 8") > 0) {
            }
            else if (b_version.toString().indexOf("IE7") > 0 || b_version.toString().indexOf("IE 7") > 0) {
            }
        }