browser="";
version="";
var os = navigator.platform;
switch (navigator.appName){
 case "Netscape":
  browser="ns";
  version=parseInt(navigator.appVersion);
 break;
 case "Microsoft Internet Explorer":
  browser = "ie";  
  if (navigator.userAgent.indexOf('MSIE 4')>0)version = 4;
  if (navigator.userAgent.indexOf('MSIE 5')>0)version = 5;
  if (navigator.userAgent.indexOf('MSIE 6')>0)version = 6;
  if (version=="")version="unknown";
 break;
  
 default:
  browser="unknown"; 
  version="unknown";
 break;
}