Case:
QUERY_WITHOUT_ARG defined and not defined.
[Automatic configuration]
Automatically detect settings. (checked) & (unchecked)
Use automatic configuration script. (checked) & (unchecked)
Address: http://unreachable/unreachable.pac
[Proxy server]
User a proxy server for your LAN. (checked)
Address: qt-test-server
Port: 3128
Bypass proxy server for local addresses. (unchecked)

Output:
"qt-test-server" 3128
Press <RETURN> to close this window...

Internet Explorer case:
Url: http://www.lagado.com/proxy-test

Output:
This request appears to have come via a proxy.