Simple:
var OSName="Unknown OS";
if (navigator.appVersion.indexOf("Win")!=-1) OSName="Windows";
if (navigator.appVersion.indexOf("Mac")!=-1) OSName="MacOS";
if (navigator.appVersion.indexOf("X11")!=-1) OSName="UNIX";
if (navigator.appVersion.indexOf("Linux")!=-1) OSName="Linux";
if (navigator.appVersion.indexOf("Linux x86_64")!=-1) OSName="Ubuntu";
var nVer = navigator.appVersion;
var nAgt = navigator.userAgent;
var browserName = navigator.appName;
var fullVersion = ''+parseFloat(navigator.appVersion);
var majorVersion = parseInt(navigator.appVersion,10);
var nameOffset,verOffset,ix;
// In Opera, the true version is after "Opera" or after "Version"
if ((verOffset=nAgt.indexOf("Opera"))!=-1) {
browserName = "Opera";
fullVersion = nAgt.substring(verOffset+6);
if ((verOffset=nAgt.indexOf("Version"))!=-1)
fullVersion = nAgt.substring(verOffset+8);
}
// In MSIE, the true version is after "MSIE" in userAgent
else if ((verOffset=nAgt.indexOf("MSIE"))!=-1) {
browserName = "Microsoft Internet Explorer";
fullVersion = nAgt.substring(verOffset+5);
}
// In Chrome, the true version is after "Chrome"
else if ((verOffset=nAgt.indexOf("Chrome"))!=-1) {
browserName = "Chrome";
fullVersion = nAgt.substring(verOffset+7);
}
// In Safari, the true version is after "Safari" or after "Version"
else if ((verOffset=nAgt.indexOf("Safari"))!=-1) {
browserName = "Safari";
fullVersion = nAgt.substring(verOffset+7);
if ((verOffset=nAgt.indexOf("Version"))!=-1)
fullVersion = nAgt.substring(verOffset+8);
}
// In Firefox, the true version is after "Firefox"
else if ((verOffset=nAgt.indexOf("Firefox"))!=-1) {
browserName = "Firefox";
fullVersion = nAgt.substring(verOffset+8);
}
// In most other browsers, "name/version" is at the end of userAgent
else if ( (nameOffset=nAgt.lastIndexOf(' ')+1) <
(verOffset=nAgt.lastIndexOf('/')) )
{
browserName = nAgt.substring(nameOffset,verOffset);
fullVersion = nAgt.substring(verOffset+1);
if (browserName.toLowerCase()==browserName.toUpperCase()) {
browserName = navigator.appName;
}
}
// trim the fullVersion string at semicolon/space if present
if ((ix=fullVersion.indexOf(";"))!=-1)
fullVersion=fullVersion.substring(0,ix);
if ((ix=fullVersion.indexOf(" "))!=-1)
fullVersion=fullVersion.substring(0,ix);
majorVersion = parseInt(''+fullVersion,10);
if (isNaN(majorVersion)) {
fullVersion = ''+parseFloat(navigator.appVersion);
majorVersion = parseInt(navigator.appVersion,10);
}
document.write(''
+'Hey! i see you\'re using '+browserName+'! <br>'
+'The full version of it is '+fullVersion+'. <br>'
+'Your major version is '+majorVersion+', <br>'
+'And your "navigator.appName" is '+navigator.appName+'. <br>'
+'Your "navigator.userAgent" is '+navigator.userAgent+'. <br>'
)
document.write('And, your OS is '+OSName+'. <br>');
_x000D_