function browserVersion() {
	var b=navigator.appName;
	if (b.indexOf('Netscape')!=-1) this.b="ns";
	else if ((b=="Opera") || (navigator.userAgent.indexOf("Opera")>0)) this.b = "opera";
	else if (b=="Microsoft Internet Explorer") this.b="ie";
	if (!b) alert('Unidentified browser.\nThis browser is not supported,');
	this.version=navigator.appVersion;
	this.v=parseInt(this.version);
	this.ns=(this.b=="ns" && this.v>=4);
	this.ns4=(this.b=="ns" && this.v==4);
	this.ns6=(this.b=="ns" && this.v==5);
	this.ns7=(this.b=="ns" && this.v==6);
	this.ns8=(this.b=="ns" && this.v==7);
	this.ns9=(this.b=="ns" && this.v==8);

	this.ie=(this.b=="ie" && this.v>=4);
	this.ie4=(this.version.indexOf('MSIE 4')>0);
	this.ie5=(this.version.indexOf('MSIE 5')>0);
	this.ie55=(this.version.indexOf('MSIE 5.5')>0);
	this.ie6=(this.version.indexOf('MSIE 6.0')>0);
	this.ie7=(this.version.indexOf('MSIE 7.0')>0);
	this.ie8=(this.version.indexOf('MSIE 8.0')>0);
	this.ie9=(this.version.indexOf('MSIE 9.0')>0);
		
	this.ie4up = (this.ie4 || this.ie5 || this.ie55 || this.ie6 || this.ie7 || this.ie8 || this.ie9);
	this.nav4up = (this.ns4 || this.ns6 || this.ns7 || this.ns8 || this.ns9);
	this.ver4up = (this.ie4up || this.nav4up);

	this.opera=(this.b=="opera");
	this.dom=(document.createElement && document.appendChild && document.getElementsByTagName)?true:false;
	this.def=(this.ie||this.dom); // most used browsers, for faster if loops
	var ua=navigator.userAgent.toLowerCase();
	if (ua.indexOf("win")>-1) this.platform="win32";
	else if (ua.indexOf("mac")>-1) this.platform="mac";
	else this.platform="other";
}
var browserVersion = new browserVersion();
var bv = browserVersion;

if (bv.nav4up) {
//location.href = "stronka_dla_ns.html" //tutaj wstaw wlasciwego urla do stronki dla netscape'iarzy
}