WebClient autentification error

Hi all!

I need connect to http server via proxy server. Proxy server needs NTLM autentification. I use class WebClient as transport. I set up proxy information (URL+credentials) while I constructWebProxyclass.

When I sent query to some site, proxy server got error (407. Proxy Authentication Required). I looked at captures with Ethereal program and saw that header "Proxy-connection: Keep Alive" was not sent to proxy. As you know, some proxy-servers don't work without this header.

When I tried to set this header manually (WebClient.Headers.Add method), method threw error "This header must be modified using the appropriate property. Parameter name: name".

What should I do to avoid this error?

[764 byte] By [Burd] at [2007-12-24]