function Is() {   
    var agt=navigator.userAgent.toLowerCase() 
    this.major = parseInt(navigator.appVersion)
	this.win   = (agt.indexOf("win")!=-1)
    this.mac    = (agt.indexOf("mac")!=-1)
    this.nav  = ((agt.indexOf('mozilla')!=-1) && ((agt.indexOf('spoofer')==-1) && (agt.indexOf('compatible') == -1)))
    this.nav3 = (this.nav && (this.major == 3))           
    this.nav4up = this.nav && (this.major >= 4)
    this.ie   = (agt.indexOf("msie") != -1)
    this.ie3  = (this.ie && (this.major == 2))
    this.ie4up  = this.ie  && (this.major >= 4)  
 }

var is;
is = new Is(); 
if (is.win && is.nav4up) {
  document.write('<LINK REL=StyleSheet HREF="/styles/krb_ns.css" TYPE="text/css">')
}
if (is.win && is.ie4up) {
  document.write('<LINK REL=StyleSheet HREF="/styles/krb.css" TYPE="text/css">')
}
if (is.mac && is.nav4up) {
 document.write('<LINK REL=StyleSheet HREF="/styles/krb_ns.css" TYPE="text/css">')
}       
if (is.mac && is.ie4up) {
  document.write('<LINK REL=StyleSheet HREF="/styles/krb.css" TYPE="text/css">')
}
if (is.nav3 || is.ie3) {
	 document.write('<LINK REL=StyleSheet HREF="/styles/krb.css" TYPE="text/css">')
}