// (1) browser vendor:
//     is_nav, is_ie, is_opera, is_hotjava, is_webtv, is_TVNavigator, is_AOLTV
// (2) browser version number:
//     is_major (integer indicating major version number: 2, 3, 4 ...)
//     is_minor (float   indicating full  version number: 2.02, 3.01, 4.04 ...)
// (3) browser vendor AND major version number
//     is_nav2, is_nav3, is_nav4, is_nav4up, is_nav6, is_nav6up, is_gecko, is_ie3,
//     is_ie4, is_ie4up, is_ie5, is_ie5up, is_ie5_5, is_ie5_5up, is_ie6, is_ie6up, is_hotjava3, is_hotjava3up,
//     is_opera2, is_opera3, is_opera4, is_opera5, is_opera5up is_galeon
// (4) JavaScript version number:
//     is_js (float indicating full JavaScript version number: 1, 1.1, 1.2 ...)
// (5) OS platform and version:
//     is_win, is_win16, is_win32, is_win31, is_win95, is_winnt, is_win98, is_winme, is_win2k
//     is_os2
//     is_mac, is_mac68k, is_macppc
//     is_unix
//     is_sun, is_sun4, is_sun5, is_suni86
//     is_irix, is_irix5, is_irix6
//     is_hpux, is_hpux9, is_hpux10
//     is_aix, is_aix1, is_aix2, is_aix3, is_aix4
//     is_linux, is_sco, is_unixware, is_mpras, is_reliant
//     is_dec, is_sinix, is_freebsd, is_bsd
//     is_vms
//
//
// Note: you don't want your Nav4 or IE4 code to "turn off" or
// stop working when new versions of browsers are released, so
// in conditional code forks, use is_ie5up ("IE 5.0 or greater") 
// is_opera5up ("Opera 5.0 or greater") instead of is_ie5 or is_opera5
// to check version in code which you want to work on future
// versions.

    // 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.  We do 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_nav2 = (is_nav && (is_major == 2));
    var is_nav3 = (is_nav && (is_major == 3));
    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_galeon = (agt.indexOf("galeon") != -1);

    var is_ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
    var is_ie3    = (is_ie && (is_major < 4));
    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_ie3 && !is_ie4);
    var is_ie5_5up =(is_ie && !is_ie3 && !is_ie4 && !is_ie5);
    var is_ie6    = (is_ie && (is_major == 4) && (agt.indexOf("msie 6.")!=-1) );
    var is_ie6up  = (is_ie && !is_ie3 && !is_ie4 && !is_ie5 && !is_ie5_5);

    // KNOWN BUG: On AOL4, returns false if IE3 is embedded browser
    // or if this is the first browser window opened.  Thus the
    // variables is_aol, is_aol3, and is_aol4 aren't 100% reliable.
    var is_aol   = (agt.indexOf("aol") != -1);
    var is_aol3  = (is_aol && is_ie3);
    var is_aol4  = (is_aol && is_ie4);
    var is_aol5  = (agt.indexOf("aol 5") != -1);
    var is_aol6  = (agt.indexOf("aol 6") != -1);

    var is_opera = (agt.indexOf("opera") != -1);
    var is_opera2 = (agt.indexOf("opera 2") != -1 || agt.indexOf("opera/2") != -1);
    var is_opera3 = (agt.indexOf("opera 3") != -1 || agt.indexOf("opera/3") != -1);
    var is_opera4 = (agt.indexOf("opera 4") != -1 || agt.indexOf("opera/4") != -1);
    var is_opera5 = (agt.indexOf("opera 5") != -1 || agt.indexOf("opera/5") != -1);
    var is_opera5up = (is_opera && !is_opera2 && !is_opera3 && !is_opera4);

    var is_webtv = (agt.indexOf("webtv") != -1); 

    var is_TVNavigator = ((agt.indexOf("navio") != -1) || (agt.indexOf("navio_aoltv") != -1)); 
    var is_AOLTV = is_TVNavigator;

    var is_hotjava = (agt.indexOf("hotjava") != -1);
    var is_hotjava3 = (is_hotjava && (is_major == 3));
    var is_hotjava3up = (is_hotjava && (is_major >= 3));

    // *** JAVASCRIPT VERSION CHECK ***
    var is_js;
    if (is_nav2 || is_ie3) is_js = 1.0;
    else if (is_nav3) is_js = 1.1;
    else if (is_opera5up) is_js = 1.3;
    else if (is_opera) is_js = 1.1;
    else if ((is_nav4 && (is_minor <= 4.05)) || is_ie4) is_js = 1.2;
    else if ((is_nav4 && (is_minor > 4.05)) || is_ie5) is_js = 1.3;
    else if (is_hotjava3up) is_js = 1.4;
    else if (is_nav6 || is_gecko) is_js = 1.5;
    // NOTE: In the future, update this code when newer versions of JS
    // are released. For now, we try to provide some upward compatibility
    // so that future versions of Nav and IE will show they are at
    // *least* JS 1.x capable. Always check for JS version compatibility
    // with > or >=.
    else if (is_nav6up) is_js = 1.5;
    // NOTE: ie5up on mac is 1.4
    else if (is_ie5up) is_js = 1.3

    // HACK: no idea for other browsers; always check for JS version with > or >=
    else is_js = 0.0;

    // *** PLATFORM ***
    var is_win   = ( (agt.indexOf("win")!=-1) || (agt.indexOf("16bit")!=-1) );
    // NOTE: On Opera 3.0, the userAgent string includes "Windows 95/NT4" on all
    //        Win32, so you can't distinguish between Win95 and WinNT.
    var is_win95 = ((agt.indexOf("win95")!=-1) || (agt.indexOf("windows 95")!=-1));

    // is this a 16 bit compiled version?
    var is_win16 = ((agt.indexOf("win16")!=-1) || 
               (agt.indexOf("16bit")!=-1) || (agt.indexOf("windows 3.1")!=-1) || 
               (agt.indexOf("windows 16-bit")!=-1) );  

    var is_win31 = ((agt.indexOf("windows 3.1")!=-1) || (agt.indexOf("win16")!=-1) ||
                    (agt.indexOf("windows 16-bit")!=-1));

    var is_winme = ((agt.indexOf("win 9x 4.90")!=-1));
    var is_win2k = ((agt.indexOf("windows nt 5.0")!=-1));

    // NOTE: Reliable detection of Win98 may not be possible. It appears that:
    //       - On Nav 4.x and before you'll get plain "Windows" in userAgent.
    //       - On Mercury client, the 32-bit version will return "Win98", but
    //         the 16-bit version running on Win98 will still return "Win95".
    var is_win98 = ((agt.indexOf("win98")!=-1) || (agt.indexOf("windows 98")!=-1));
    var is_winnt = ((agt.indexOf("winnt")!=-1) || (agt.indexOf("windows nt")!=-1));
    var is_win32 = (is_win95 || is_winnt || is_win98 || 
                    ((is_major >= 4) && (navigator.platform == "Win32")) ||
                    (agt.indexOf("win32")!=-1) || (agt.indexOf("32bit")!=-1));

    var is_os2   = ((agt.indexOf("os/2")!=-1) || 
                    (navigator.appVersion.indexOf("OS/2")!=-1) ||   
                    (agt.indexOf("ibm-webexplorer")!=-1));

    var is_mac    = (agt.indexOf("mac")!=-1);
    // hack ie5 js version for mac
    if (is_mac && is_ie5up) is_js = 1.4;
    var is_mac68k = (is_mac && ((agt.indexOf("68k")!=-1) || 
                               (agt.indexOf("68000")!=-1)));
    var is_macppc = (is_mac && ((agt.indexOf("ppc")!=-1) || 
                                (agt.indexOf("powerpc")!=-1)));

    var is_sun   = (agt.indexOf("sunos")!=-1);
    var is_sun4  = (agt.indexOf("sunos 4")!=-1);
    var is_sun5  = (agt.indexOf("sunos 5")!=-1);
    var is_suni86= (is_sun && (agt.indexOf("i86")!=-1));
    var is_irix  = (agt.indexOf("irix") !=-1);    // SGI
    var is_irix5 = (agt.indexOf("irix 5") !=-1);
    var is_irix6 = ((agt.indexOf("irix 6") !=-1) || (agt.indexOf("irix6") !=-1));
    var is_hpux  = (agt.indexOf("hp-ux")!=-1);
    var is_hpux9 = (is_hpux && (agt.indexOf("09.")!=-1));
    var is_hpux10= (is_hpux && (agt.indexOf("10.")!=-1));
    var is_aix   = (agt.indexOf("aix") !=-1);      // IBM
    var is_aix1  = (agt.indexOf("aix 1") !=-1);    
    var is_aix2  = (agt.indexOf("aix 2") !=-1);    
    var is_aix3  = (agt.indexOf("aix 3") !=-1);    
    var is_aix4  = (agt.indexOf("aix 4") !=-1);    
    var is_linux = (agt.indexOf("inux")!=-1);
    var is_sco   = (agt.indexOf("sco")!=-1) || (agt.indexOf("unix_sv")!=-1);
    var is_unixware = (agt.indexOf("unix_system_v")!=-1); 
    var is_mpras    = (agt.indexOf("ncr")!=-1); 
    var is_reliant  = (agt.indexOf("reliantunix")!=-1);
    var is_dec   = ((agt.indexOf("dec")!=-1) || (agt.indexOf("osf1")!=-1) || 
           (agt.indexOf("dec_alpha")!=-1) || (agt.indexOf("alphaserver")!=-1) || 
           (agt.indexOf("ultrix")!=-1) || (agt.indexOf("alphastation")!=-1)); 
    var is_sinix = (agt.indexOf("sinix")!=-1);
    var is_freebsd = (agt.indexOf("freebsd")!=-1);
    var is_bsd = (agt.indexOf("bsd")!=-1);
    var is_unix  = ((agt.indexOf("x11")!=-1) || is_sun || is_irix || is_hpux || 
                 is_sco ||is_unixware || is_mpras || is_reliant || 
                 is_dec || is_sinix || is_aix || is_linux || is_bsd || is_freebsd);

    var is_vms   = ((agt.indexOf("vax")!=-1) || (agt.indexOf("openvms")!=-1));
	
	
//	 Gecko vendor/version values Browser Vendor version 
// Netscape 6.0           Netscape6       6.0 
// Netscape 6.01          Netscape6       6.01 
// Netscape 6.1           Netscape6       6.1 
// Netscape 6.2           Netscape6       6.2 
// Netscape 6.2.1         Netscape6       6.2.1 
// Netscape 6.2.2         Netscape6       6.2.2 
// Netscape 6.2.3         Netscape6       6.2.3 
// CompuServe 7.0         CS 2000 7.0     7.0 
// Netscape 7 Preview Release 1 Netscape  7.0b1 
// Netscape 7.0           Netscape        7.0 
// Netscape 7.01          Netscape        7.01 

//in Gecko 0.9.0 (Netscape 6.1 in Gecko 0.9.2), navigator.userAgent contains the CVS branch tag which was used to create the version of Gecko being used in the browser. The branch tag is contained in the comment area of the user agent string and follows the string 'rv:'. 

//      Mozilla/5.0 (...; rv:a.b.c) Gecko/CCYYMMDD Vendor/version
//    Gecko browsers which are built from the same branch share the same basic version of Netscape Gecko and can be treated similarly when dealing with HTML, CSS, JavaScript, etc. For example, Netscape 6.2, 6.2.1, 6.2.2, 6.2.3 and CompuServe 7 are all built from the 0.9.4 branch are similar. 

//Gecko Branch Tags Browser Branch Tag 
//Netscape 6.0 contained M18 rather than the rv value 
//Netscape 6.1 0.9.2 
//Netscape 6.2 0.9.4 
//Netscape 6.2.1 0.9.4 
//Netscape 6.2.2 0.9.4.1 
//Netscape 6.2.3 0.9.4.1 
//CompuServe 7 0.9.4.2 
//Netscape 7.0 1.0.1 
//Netscape 7.01 1.0.2 

//all versions of Netscape 6.2 and CompuServe 7 were created from the 0.9.4 branch. The distinction between 0.9.4, 0.9.4.1, 0.9.4.2 is minor.

// return the rv value of a Gecko user agent
// as a floating point number. 
// returns -1 for non-gecko browsers, 
//          0 for pre Netscape 6.1/Gecko 0.9.1 browsers
//          number > 0 where each portion of 
//          the rv value delimited by . 
//          will be treated as value out of 100.
//          e.g. for rv: 3.12.42, 
//          getGeckoRv() returns 3.1242
//          

function geckoGetRv()
{
  if (navigator.product != 'Gecko')
  {
    return -1;
  }
  var rvValue = 0;
  var ua      = navigator.userAgent.toLowerCase();
  var rvStart = ua.indexOf('rv:');
  var rvEnd   = ua.indexOf(')', rvStart);
  var rv      = ua.substring(rvStart+3, rvEnd);
  var rvParts = rv.split('.');
  var exp     = 1;

  for (var i = 0; i < rvParts.length; i++)
  {
    var val = parseInt(rvParts[i]);
    rvValue += val / exp;
    exp *= 100;
  }
  return rvValue;
}

// determine if the browser is any Netscape Gecko
// branch >= 1.0.1 or Netscape 6.2.x/CompuServe 7 
// built after August 1, 2002

// determine if the browser is any Netscape Gecko
// branch >= 1.0.1 or Netscape 6.2.x/CompuServe 7 
// built after August 1, 2002

var rv    = geckoGetRv();
var found = false;

if (rv >= 0)
{
  // Gecko browser
  if (navigator.productSub > '20020801')
  {
    if (rv >= 1.0001)
    {
      found = true;
    }
    else if (rv >= 0.0904 && rv < 0.0905)
    {
      if (navigator.vendor == 'Netscape6' || navigator.vendor == 'CS 2000 7.0')
      {
        found = true;
      }
    }
  }
}