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="../include/css/style_nn.css">')
}
  if (is.mac && is.nav4up) {
  document.write('<LINK REL="stylesheet" HREF="../include/css/style_ie.css">')
} 
  if (is.win && is.ie4up) {
  document.write('')
}    
  if (is.mac && is.ie4up) {
  document.write('')
}