function Is() {
	agent = navigator.userAgent.toLowerCase();
	this.major=parseInt(navigator.appVersion);
	this.minor=parseFloat(navigator.appVersion);
	this.ns=((agent.indexOf('mozilla') != -1) &&
	((agent.indexOf('spoofer') == -1) && (agent.indexOf('compartible') == -1)));
	this.ns4=(this.ns && (this.major==4));
	this.ns6=(this.ns && (this.major>=5));
	this.ie=(agent.indexOf("msie") != -1);
	this.ie3=(this.ie && (this.major < 4));
	this.ie4=(this.ie && (this.major ==4) && (agent.indexOf("msie 5.0") == -1));
	this.ie5=(this.ie && (this.major ==4) && (agent.indexOf("msie 5.0") != -1));
	this.ie55=(this.ie &&(this.major ==4) && (agent.indexOf("msie5.5") != -1));
	this.ie6=(this.ie && (agent.indexOf("msie 6.0") != -1));
}

var is = new Is();
var IEtrue=false;
var NN6=false;

if (is.ie3 || is.ie4 || is.ie5 || is.ie55 || is.ie6)
  IEtrue=true;
else
{
  if (is.ns4) {
    IEtrue=false;
    NN6=false;}
  else if (is.ns6) NN6=true;
//  else
//    alert("browser type is unknown");
}