Определения браузера в JavaScript

//Firefox detector 2/3 by DoctorDan
FF=/a/[-1]=='a'
 
//Firefox 3
FF3=(function x(){})[-5]=='x'
 
//Firefox 2
FF2=(function x(){})[-6]=='x'
 
//IE
IE='\v'=='v'
 
//Safari
Saf=/a/.__proto__=='//'
 
//Chrome
Chr=/source/.test((/a/.toString+''))

B=(function x(){})[-5]=='x'?'FF3':(function x(){})[-6]=='x'?'FF2':'\v'=='v'?'IE':/a/.__proto__=='//'?'Saf':/s/.test(/a/.toString)?'Chr':'Op';