//browser detection
var isMinNS4 = (navigator.appName.indexOf("Netscape") >= 0 && parseFloat(navigator.appVersion) >= 4&&parseFloat(navigator.appVersion) < 5) ? 1 : 0;
var isMinNS6 = (isMinNS4 && navigator.userAgent.indexOf("Gecko")>=0) ? 1 : 0;
var isMinIE4 = (document.all) ? 1 : 0;
var isMinIE5 = (isMinIE4 && navigator.appVersion.indexOf("5.")) >= 0 ? 1 : 0;
var isDOM = (document.getElementById) ? 1 : 0;
var isMac = (navigator.appVersion.indexOf("Mac",0) >= 0) ? 1 : 0;
var isOpera = (navigator.userAgent.toLowerCase().indexOf('opera') >= 0) ? 1 : 0;

// exclude NS 4 and IE5-Mac
if (isMinNS4) {
	window.location.href="upgrade.html";
}

if (isMac && navigator.appVersion.indexOf("MSIE 5")>-1) {
	if (isOpera) {
	//do nothing
	} else {
	window.location.href="upgrade.html";
	}
}