var nav = navigator.appName;
var version= navigator.appVersion;
var num_version = version.substring(0,1);
var useragent = navigator.userAgent;
vartest = useragent.substring(0,7);
if (nav == 'Netscape' && num_version <= 4){
   var netscape=47;
}
else{
   var netscape = 0;
}
if(document.all){
   var IE4 = 'yes';
}
else{
   var IE4 = 'no';
}