// Ultimate client-side JavaScript client sniff. Version 3.03
// (C) Netscape Communications 1999-2001.  Permission granted to reuse and distribute.
// Revised 17 May 99 to add is.nav5up and is.ie5up (see below).
// Revised 21 Nov 00 to add is.gecko and is.ie5_5 Also Changed is.nav5 and is.nav5up to is.nav6 and is.nav6up
// Revised 22 Feb 01 to correct Javascript Detection for IE 5.x, Opera 4, 
//                      correct Opera 5 detection
//                      add support for winME and win2k
//                      synch with browser-type-oo.js
//                      add is.aol5, is.aol6
// Revised 26 Mar 01 to correct Opera detection
// Revised 02 Oct 01 to add IE6 detection

// Everything you always wanted to know about your JavaScript client
// but were afraid to ask ... "Is" is the constructor function for "is" object,
// which has properties indicating:
// (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.aol3, is.aol4, is.aol5, is.aol6
// (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
//
// See http://www.it97.de/JavaScript/JS_tutorial/bstat/navobj.html and
// http://www.it97.de/JavaScript/JS_tutorial/bstat/Browseraol.html
// for detailed lists of userAgent strings.
//
// Note: you don't want your Nav4 or IE4 code to "turn off" or
// stop working when Nav5 and IE5 (or later) are released, so
// in conditional code forks, use is.nav4up ("Nav4 or greater")
// and is.ie4up ("IE4 or greater") instead of is.nav4 or is.ie4
// to check version in code which you want to work on future
// versions.


function Is () {   // convert all characters to lowercase to simplify testing
	var agt=navigator.userAgent.toLowerCase();
	this.agt = agt;
	
	// *** BROWSER VERSION ***
	// Note: On IE5, these return 4, so use is.ie5up to detect IE5
	// or is.ie6up to detect IE6.

	this.major = parseInt(navigator.appVersion);
	this.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.
	this.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));
	this.nav2 = (this.nav && (this.major == 2));
	this.nav3 = (this.nav && (this.major == 3));
	this.nav4 = (this.nav && (this.major == 4));
	this.nav4up = (this.nav && (this.major >= 4));
	this.navonly	  = (this.nav && ((agt.indexOf(";nav") != -1) ||
			      (agt.indexOf("; nav") != -1)) );
	this.nav6 = (this.nav && (this.major == 5));
	this.nav6up = (this.nav && (this.major >= 5));
	this.gecko = (agt.indexOf('gecko') != -1);


	this.ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
	this.ie3    = (this.ie && (this.major < 4));
	this.ie4    = (this.ie && (this.major == 4) && (agt.indexOf("msie 4")!=-1) );
	this.ie4up  = (this.ie  && (this.major >= 4));
	this.ie5    = (this.ie && (this.major == 4) && (agt.indexOf("msie 5.0")!=-1) );
	this.ie5_5  = (this.ie && (this.major == 4) && (agt.indexOf("msie 5.5") !=-1));
	this.ie5up  = (this.ie  && !this.ie3 && !this.ie4);
	this.ie5_5up =(this.ie && !this.ie3 && !this.ie4 && !this.ie5);
	this.ie6    = (this.ie && (this.major == 4) && (agt.indexOf("msie 6.")!=-1) );
	this.ie6up  = (this.ie  && !this.ie3 && !this.ie4 && !this.ie5 && !this.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.
	this.aol   = (agt.indexOf("aol") != -1);
	this.aol3  = (this.aol && this.ie3);
	this.aol4  = (this.aol && this.ie4);
	this.aol5  = (agt.indexOf("aol 5") != -1);
	this.aol6  = (agt.indexOf("aol 6") != -1);

	this.opera = (agt.indexOf("opera") != -1);
	this.opera2 = (agt.indexOf("opera 2") != -1 || agt.indexOf("opera/2") != -1);
	this.opera3 = (agt.indexOf("opera 3") != -1 || agt.indexOf("opera/3") != -1);
	this.opera4 = (agt.indexOf("opera 4") != -1 || agt.indexOf("opera/4") != -1);
	this.opera5 = (agt.indexOf("opera 5") != -1 || agt.indexOf("opera/5") != -1);
	this.opera6 = (agt.indexOf("opera 6") != -1 || agt.indexOf("opera/6") != -1);
	this.opera7 = (agt.indexOf("opera 7") != -1 || agt.indexOf("opera/7") != -1);
	this.opera5up = (this.opera && !this.opera2 && !this.opera3 && !this.opera4);

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

	this.TVNavigator = ((agt.indexOf("navio") != -1) || (agt.indexOf("navio_aoltv") != -1)); 
	this.AOLTV = this.TVNavigator;

	this.hotjava = (agt.indexOf("hotjava") != -1);
	this.hotjava3 = (this.hotjava && (this.major == 3));
	this.hotjava3up = (this.hotjava && (this.major >= 3));

	// *** JAVASCRIPT VERSION CHECK ***
	if (this.nav2 || this.ie3) this.js = 1.0;
	else if (this.nav3) this.js = 1.1;
	else if (this.opera5up) this.js = 1.3;
	else if (this.opera) this.js = 1.1;
	else if ((this.nav4 && (this.minor <= 4.05)) || this.ie4) this.js = 1.2;
	else if ((this.nav4 && (this.minor > 4.05)) || this.ie5) this.js = 1.3;
	else if (this.hotjava3up) this.js = 1.4;
	else if (this.nav6 || this.gecko) this.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 (this.nav6up) this.js = 1.5;
	// note ie5up on mac is 1.4
	else if (this.ie5up) this.js = 1.3

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

	// *** PLATFORM ***
	this.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.
	this.win95 = ((agt.indexOf("win95")!=-1) || (agt.indexOf("windows 95")!=-1));

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

	this.win31 = ((agt.indexOf("windows 3.1")!=-1) || (agt.indexOf("win16")!=-1) ||
			(agt.indexOf("windows 16-bit")!=-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".
	this.win98 = ((agt.indexOf("win98")!=-1) || (agt.indexOf("windows 98")!=-1));
	this.winnt = ((agt.indexOf("winnt")!=-1) || (agt.indexOf("windows nt")!=-1));
	this.win32 = (this.win95 || this.winnt || this.win98 || 
			((this.major >= 4) && (navigator.platform == "Win32")) ||
			(agt.indexOf("win32")!=-1) || (agt.indexOf("32bit")!=-1));

	this.winme = ((agt.indexOf("win 9x 4.90")!=-1));
	this.win2k = ((agt.indexOf("windows nt 5.0")!=-1));

	this.os2   = ((agt.indexOf("os/2")!=-1) || 
			(navigator.appVersion.indexOf("OS/2")!=-1) ||	
			(agt.indexOf("ibm-webexplorer")!=-1));

	this.mac    = (agt.indexOf("mac")!=-1);
	// hack ie5 js version for mac
	if (this.mac && this.ie5up) this.js = 1.4;
	this.mac68k = (this.mac && ((agt.indexOf("68k")!=-1) || 
				   (agt.indexOf("68000")!=-1)));
	this.macppc = (this.mac && ((agt.indexOf("ppc")!=-1) || 
				    (agt.indexOf("powerpc")!=-1)));

	this.sun   = (agt.indexOf("sunos")!=-1);
	this.sun4  = (agt.indexOf("sunos 4")!=-1);
	this.sun5  = (agt.indexOf("sunos 5")!=-1);
	this.suni86= (this.sun && (agt.indexOf("i86")!=-1));
	this.irix  = (agt.indexOf("irix") !=-1);    // SGI
	this.irix5 = (agt.indexOf("irix 5") !=-1);
	this.irix6 = ((agt.indexOf("irix 6") !=-1) || (agt.indexOf("irix6") !=-1));
	this.hpux  = (agt.indexOf("hp-ux")!=-1);
	this.hpux9 = (this.hpux && (agt.indexOf("09.")!=-1));
	this.hpux10= (this.hpux && (agt.indexOf("10.")!=-1));
	this.aix   = (agt.indexOf("aix") !=-1);      // IBM
	this.aix1  = (agt.indexOf("aix 1") !=-1);    
	this.aix2  = (agt.indexOf("aix 2") !=-1);    
	this.aix3  = (agt.indexOf("aix 3") !=-1);    
	this.aix4  = (agt.indexOf("aix 4") !=-1);    
	this.linux = (agt.indexOf("inux")!=-1);
	this.sco   = (agt.indexOf("sco")!=-1) || (agt.indexOf("unix_sv")!=-1);
	this.unixware = (agt.indexOf("unix_system_v")!=-1); 
	this.mpras    = (agt.indexOf("ncr")!=-1); 
	this.reliant  = (agt.indexOf("reliantunix")!=-1);
	this.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)); 
	this.sinix = (agt.indexOf("sinix")!=-1);
	this.freebsd = (agt.indexOf("freebsd")!=-1);
	this.bsd = (agt.indexOf("bsd")!=-1);
	this.unix  = ((agt.indexOf("x11")!=-1) || this.sun || this.irix || this.hpux || 
		     this.sco ||this.unixware || this.mpras || this.reliant || 
		     this.dec || this.sinix || this.aix || this.linux || this.bsd || this.freebsd);

	this.vms   = ((agt.indexOf("vax")!=-1) || (agt.indexOf("openvms")!=-1));
}

var browser_is = new Is();

function is_browser_supported() {
	// alert('You are running: ' +  browser_is.agt);
	// declare vars
	var reason = '';
	
	// create browser sniffer oject

	// Reject known non-working browsers
	// IE 4.0 and previous
	if (browser_is.ie3 || browser_is.ie4) return false;

	// Navigator 4.7 and previous
	if (browser_is.nav2 || browser_is.nav3 || browser_is.nav4) return false;

	// Opera 7 and previous
	if (browser_is.opera2 || browser_is.opera3 || browser_is.opera4 || browser_is.opera5 || browser_is.opera6) return false;

	// Return true for known to work browsers
	if (browser_is.gecko) return true;
	if (browser_is.ie5up) return true;

	// If browser is unknown, do a feature and functionality check
	feature = new Array()

	// check if browser supports the push method to an array object
	if (!feature.push) {
		reason += ' \n Array object does not support push method. ';
	}

	// Check for document feature
	feature.length = 0;
	feature.push('getElementById');
	feature.push('createElement');
	feature.push('implementation');

	for (var i in feature) {
		var f = 'document.' + feature[i];
		if (!f) {
			reason += '\n' + feature[i] + ' missing.';
		}
	}

	if (reason) {
		reason = 'Your web browser has the following features missing to view NiagaraFalls.ca.\n' + reason;
		alert(reason);
		return false;
	}

	if (!document.implementation.hasFeature) {
		alert('Your browser does not support the hasFeature() method.')
		return false;
	}

	// Check for DOM features
	// reset array
	feature.length = 0;
	feature.push('HTML');

	/*
	feature.push('XML');
	feature.push('Views');
	feature.push('Stylesheets');
	feature.push('CSS');
	feature.push('CSS2');
	feature.push('Events');
	feature.push('UIEvents');
	feature.push('MouseEvents');
	feature.push('MutationEvents');
	feature.push('HTMLEvents');
	feature.push('Traversal');
	feature.push('Range');
	*/
	
	for (var i in feature) {
		if (!document.implementation.hasFeature(feature[i],'1.0')) {
			reason += '\n - ' + feature[i] + ' compliance.';
			// alert(feature[i]);
		}
	}

	if (reason) {
		reason = 'Your web browser has the following features missing to view NiagaraFalls.ca.\n' + reason;
		alert(reason)
		//return false;
	}

	// Check for element features
	// reset array
	feature.length = 0;
	feature.push('setAttribute');
	feature.push('style');
	feature.push('innerHTML');

	for (var i in feature) {
		var f = 'document.documentElement.' + feature[i];
		if (!f) {
			reason += '\n el.' + feature[i] + ' missing.';
		}
	}

	if (reason) {
		reason = 'Your web browser has the following features missing to view NiagaraFalls.ca.\n' + reason;
		alert(reason)
		return false;
	}

	// Check browser version
	return true
}