(407) Proxy Authentication Required

[C# Programming]

Hello Expert

I am very new to .net and i am trying to read some data from web site and i have written following pi

WebRequest request;
WebResponse response;
IWebProxy test = System.Net.WebRequest.GetSystemWebProxy();
test.Credentials = CredentialCache.DefaultCredentials;
request = System.Net.WebRequest.Create(
any URL name)
request.Proxy = test;
response = request.GetResponse();

it is giving some error at response = request.GetResponse();and error is
The remote server returned an error: (407) Proxy Authentication Required.

I am accessing net though some proxy


Thanks in advance
RYK