var _ua = navigator.userAgent;
    var rv = -1;
     
    //IE 11,10,9,8
    var trident = _ua.match(/Trident\/(\d.\d)/i);
    if( trident != null )
    {
        if( trident[1] == "7.0" ) return rv = "IE" + 11;
        if( trident[1] == "6.0" ) return rv = "IE" + 10;
        if( trident[1] == "5.0" ) return rv = "IE" + 9;
        if( trident[1] == "4.0" ) return rv = "IE" + 8;
    }
     
    //IE 7...
    if( navigator.appName == 'Microsoft Internet Explorer' ) return rv = "IE" + 7;
     
    /*
    var re = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if(re.exec(_ua) != null) rv = parseFloat(RegExp.$1);
    if( rv == 7 ) return rv = "IE" + 7; 
    */
     
    //other
    var agt = _ua.toLowerCase();
    if (agt.indexOf("chrome") != -1) return 'Chrome';
    if (agt.indexOf("opera") != -1) return 'Opera'; 
    if (agt.indexOf("staroffice") != -1) return 'Star Office'; 
    if (agt.indexOf("webtv") != -1) return 'WebTV'; 
    if (agt.indexOf("beonex") != -1) return 'Beonex'; 
    if (agt.indexOf("chimera") != -1) return 'Chimera'; 
    if (agt.indexOf("netpositive") != -1) return 'NetPositive'; 
    if (agt.indexOf("phoenix") != -1) return 'Phoenix'; 
    if (agt.indexOf("firefox") != -1) return 'Firefox'; 
    if (agt.indexOf("safari") != -1) return 'Safari'; 
    if (agt.indexOf("skipstone") != -1) return 'SkipStone'; 
    if (agt.indexOf("netscape") != -1) return 'Netscape'; 
    if (agt.indexOf("mozilla/5.0") != -1) return 'Mozilla';