<!--
    // convert all characters to lowercase to simplify testing
    var agt = navigator.userAgent.toLowerCase();

    // *** BROWSER VERSION ***
    // Note: On IE5, these return 4, so use is_ie5up to detect IE5.
    var is_major = parseInt(navigator.appVersion);
    var is_minor = parseFloat(navigator.appVersion);

    // Note: Opera and WebTV spoof Navigator.  This does strict client detection.
    // If you want to allow spoofing, take out the tests for opera and webtv.
    var is_nav     = ((agt.indexOf('mozilla') != -1) && (agt.indexOf('spoofer') == -1)
                   && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera') == -1)
                   && (agt.indexOf('webtv') == -1) && (agt.indexOf('hotjava') == -1));
    var is_nav4    = (is_nav && (is_major == 4));
    var is_nav4up  = (is_nav && (is_major >= 4));
    var is_navonly = (is_nav && ((agt.indexOf(";nav") != -1) || (agt.indexOf("; nav") != -1)) );
    var is_nav6    = (is_nav && (is_major == 5));
    var is_nav6up  = (is_nav && (is_major >= 5));
    var is_gecko   = (agt.indexOf('gecko') != -1);

    var is_ie      = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
    var is_ie4     = (is_ie && (is_major == 4) && (agt.indexOf("msie 4")!=-1) );
    var is_ie4up   = (is_ie && (is_major >= 4));
    var is_ie5     = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")!=-1) );
    var is_ie5_5   = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.5") !=-1));
    var is_ie5up   = (is_ie && !is_ie4);
    var is_ie5_5up = (is_ie && !is_ie4 && !is_ie5);
    var is_ie6     = (is_ie && (is_major == 4) && (agt.indexOf("msie 6.")!=-1) );
    var is_ie6up   = (is_ie && !is_ie4 && !is_ie5 && !is_ie5_5);
//-->