var u = "Browser"; if (this.isIPad) { u = "iPad" } else { if (this.isDDGIgnore) { u = "Ignore" } else { if (/seamonkey/.test(x)) { u = "SeaMonkey" } else { if (/iceape/.test(x)) { u = "Iceape" } else { if (/palemoon/.test(x)) { u = "PaleMoon" } else { if (this.isFirefox) { u = "Firefox" } else { if (this.isAndroid) { u = "Android" } else { if (/xbox/.test(x)) { u = "xBox" } else { if (/midori/.test(x)) { u = "Midori" } else { if (/opr/.test(x)) { u = "Opera" } else { if (/maxthon/.test(x)) { u = "Maxthon" } else { if (this.isYandex) { u = "Yandex" } else { if (/vivaldi/.test(x)) { u = "Vivaldi" } else { if (this.isChrome) { u = "Chrome" } else { if (/fennec/.test(x)) { u = "Fennec" } else { if (/epiphany/.test(x)) { u = "Epiphany" } else { if (this.isFirefox) { u = "Firefox" } else { if (/uzbl/.test(x)) { u = "Uzbl" } else { if (this.isEdge) { u = "Edge" } else { if (this.isIE && navigator.platform === "Win64" && !k() && Modernizr.touch && document.documentElement.clientWidth == screen.width) { u = "IEMetro" } else { if (this.isIE) { u = "IE" } else { if (this.isOpera) { u = "Opera" } else { if (this.isIPhone) { u = "iPhone" } else { if (/arora/.test(x)) { u = "Arora" } else { if (this.isSafari) { u = "Safari" } else { if (this.isKonqueror) { u = "Konqueror" } else { if (this.isBlackberry) { u = "Blackberry" } else { if (/phantomjs/.test(x)) { u = "PhantomJS" } else { if (this.isIDevice) { u = "iOS" } } } } } } } } } } } } } } } } } } } } } } } } } } } } }

Found when looking at facebook.com code and formatting using google chrome developer tools.