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) || (agt.indexOf("windows 2000")!=-1));
	var is_winxp = ((agt.indexOf("windows nt 5.1")!=-1) || (agt.indexOf("windows xp")!=-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);
	if (is_mac) { is_win = !is_mac; }
	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);
	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);
	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));