Prototype.Browser = {
	IE:     !!(window.attachEvent && !window.opera),
	Opera:  !!window.opera,
	WebKit: document.childNodes && !document.all && !navigator.taintEnabled,
	Gecko:  (document.getBoxObjectFor != null),
	MobileSafari: !!navigator.userAgent.match(/Apple.*Mobile.*Safari/)
};

Object.extend(Prototype.Browser, {
     WebKit419: Prototype.Browser.WebKit && (Prototype.BrowserFeatures.XPath),
     WebKit420: Prototype.Browser.WebKit && (!Prototype.BrowserFeatures.XPath),
     IE6:      Prototype.Browser.IE && (typeof window.XMLHttpRequest == "undefined"),
     IE7:      Prototype.Browser.IE && (typeof window.XMLHttpRequest == "object")
});