It fixed the problem that proxy switching may fail if you open too many Firefox windows.
Elite Proxy Switcher (EPS) is a professional proxy tester and proxy switcher for your browsers. It can test the details (speed, anonymity, country and whether ssl, gateway, dangerous or CoDeeN/Planetlab) of the proxies and automatically change the proxy settings of your browsers (Internet Explorer or Mozilla Firefox).
Homepage:
http://www.eliteproxyswitcher.com/Download it here:
http://www.eliteproxyswitcher.com/EPS_setup.exeOnline help document:
http://www.eliteproxyswitcher.com/help.php