Configuring your browser with "Proxy Auto-Config File" proxy.pac

Configuring your browser with "Proxy Auto-Config File" proxy.pac
Definition
The proxy auto-config (.pac) file defines how user agents can automatically choose the appropriate access method for fetching a given URL. See Wikipedia article for more detailed description.
Firefox
Go to Tools -> Options -> General -> Connection Settings. Select the option to enter an automatic proxy configuration URL. Enter http://rosinstrument.com/cgi-bin/proxy.pac and click OK twice.
Firefox 2
Go to Tools -> Options -> Advanced -> Network -> Settings. Select the option to enter an automatic proxy configuration URL. Enter http://rosinstrument.com/cgi-bin/proxy.pac and click OK twice.
Internet Explorer
Go to Tools -> Internet Options -> Connections. If you use a dialup connection, select it and click Settings. Otherwise, click LAN Settings. Select the option to use an automatic configuration script. Make sure no other options are selected. Enter http://rosinstrument.com/cgi-bin/proxy.pac and click OK twice.
only SOCKS, CONNECT or HTTP selection

* to select only HTTP proxy use http://rosinstrument.com/cgi-bin/http.pac as configuration script.
* to select only CONNECT (HTTPS) proxy use http://rosinstrument.com/cgi-bin/https.pac as configuration script.
* to select only SOCKS proxy use http://rosinstrument.com/cgi-bin/socks.pac as configuration script.