var version = {};
var userAgent = navigator.userAgent.toLowerCase();
version .isFirefox = /firefox/.test(userAgent);
version .isOpera = /opera/.test(userAgent);
version .isSafari = /webkit/.test(userAgent);
version .isIE = /msie/.test(userAgent) && !/opera/.test(userAgent);
version .isIE6 = /msie 6/i.test(navigator.appVersion);
version .browserVersion = (userAgent.match( /.+(?:rv|it|ra|ie)[//: ]([/d.]+)/ ) || [0,'0'])[1];
version .isIElt8 = this.isIE && (this.browserVersion-0 < 8);