function Is() {
			var agt=navigator.userAgent.toLowerCase()
			this.major = parseInt(navigator.appVersion)
			this.minor = parseFloat(navigator.appVersion)
			this.nav = ((agt.indexOf('mozilla')!=-1) && ((agt.indexOf('spoofer')==-1) && (agt.indexOf('compatible') == -1)))
			this.nav4up = this.nav && (this.major >= 4)
			this.ie = (agt.indexOf("msie") != -1)
			this.ie4up = this.ie && (this.major >= 4)
			isMac = (navigator.appVersion.indexOf("Mac") != -1)
		}
		var is = new Is()
		if (isMac) {
			if (is.nav4up) {
				document.write('<link rel="STYLESHEET" type="text/css" href="/css/nav.css">')
			}
			if (is.ie4up) {
				document.write('<link rel="STYLESHEET" type="text/css" href="/css/ie.css">')
			}
		} else {
			if (is.nav4up) {
				document.write('<link rel="STYLESHEET" type="text/css" href="/css/nav.css">')
			}else if (is.ie4up) {
				document.write('<link rel="STYLESHEET" type="text/css" href="/css/ie.css">')
			} else {
				document.write('<link rel="STYLESHEET" type="text/css" href="/css/nav.css">')			
			}
		}