WebBrowser-Authorization for Reporting Services

Hi,

i have a .Net-application where i use ReportingServices2008. There i build an url with parameters to show the finished report in my wpf WebBrowser. This works fine...but now there is the login-popup for credentials and i don't want, that the user must sign in. I want to do that  automatic in background.

I searched some days on Google and got the conclusion that Ntlm with webbrowser is very difficult so i changed authorization to Basic for my ReportServer.

Now i shuould submit my credentials in this way:

string authHeader = "Authorization: BASIC "+ Convert.ToBase64String(Encoding.ASCII.GetBytes("user"+ ":"+ "pwd")) + ""+ System.Environment.NewLine;
browser.Navigate(uri, string.Empty, null, authHeader);

But it didn't work...the login-pop is still occuring when i open the url with my WebBrowser

I found an article about anonymous access on ReportingServices but i dont want that everyone can do everything on the reports.Further i look forward to change to SQLServer 2008R2 and it seems, that ther isn't a soloution for anonymous accsess on ReportingServices jet.

In hope, that someone can help me

Thanks

Doriath21