var nVer = navigator.appVersion;
var nAgt = navigator.userAgent;
var browserName = navigator.appName;
var fullVersion, verOffset, majorVersion;
// In Chrome, the true version is after "Chrome".
if ((verOffset = nAgt.indexOf('Chrome')) !== -1)
fullVersion = nAgt.substring(verOffset + 7);
majorVersion = parseInt('' + fullVersion, 10);
// In Safari, the true version is after "Safari" or after "Version".
else if ((verOffset = nAgt.indexOf('Safari')) !== -1)
fullVersion = nAgt.substring(verOffset + 7);
if ((verOffset = nAgt.indexOf('Version')) !== -1)
fullVersion = nAgt.substring(verOffset + 8);
majorVersion = parseInt('' + fullVersion, 10);
// In Firefox, the true version is after "Firefox".
else if ((verOffset = nAgt.indexOf('Firefox')) != -1)
fullVersion = nAgt.substring(verOffset + 8);
majorVersion = parseInt('' + fullVersion, 10);
else if ((verOffset = nAgt.indexOf('Edge')) != -1)
fullVersion = nAgt.substring(verOffset + 5);
majorVersion = parseInt('' + fullVersion, 10);