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('compatible') == -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("msie 5.5") != -1));
this.ie6 = (this.ie && (agent.indexOf("msie 6.0")!=-1) );
}

 var is = new Is();

if(navigator.userAgent.indexOf("Mac") !=-1){
 
if (is.ie4||is.ie5||is.ie55||is.ie6){ //for IE
	document.write('<link rel="stylesheet" href="../css/nav_fix.css" type="text/css" />');
	}
	else
	document.write('<script src="../js/nav.js"></script>');
}
else{
	if (is.ie5){
		document.write('<link rel="stylesheet" href="../css/nav_fix.css" type="text/css" />');
		}
		else
		document.write('<script src="../js/nav.js"></script>');
	}