var tempN = navigator.appName;
var tempV = parseInt(navigator.appVersion);
var myplatform = navigator.platform; 
var tempUA = navigator.userAgent;
var pattern= /Opera/;
var oper=tempUA.match(pattern);

     if (tempN =="Netscape" && tempV >=4 && tempV < 5)       { var version="n4"; }
else if (tempN =="Netscape" && tempV >= 5)                   { var version="n6"; }
else if (tempN =="Microsoft Internet Explorer" && tempV >=4) { var version="ie"; }
else if (tempN =="Opera" && tempV >=5)                       { var version="op"; }
else { var version="xx";}