Specialtegn forsvinder ved brug af StreamReader

Hvad kan jeg gøre for at StreamReaderen ikke æder de danske karakterer æ ø å i htmlen???

public string RequestHTML(string url) {

// Create a request for the URL.        
WebRequest request = WebRequest.Create(url);
// If required by the server, set the credentials.
request.Credentials = CredentialCache.DefaultCredentials;
// Get the response.
HttpWebResponse response = (HttpWebResponse)request.GetResponse();

WebHeaderCollection myWebHeaderCollection = response.Headers;

// Get the stream containing content returned by the server.
Stream dataStream = response.GetResponseStream();
// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);
// Read the content.
string responseFromServer = reader.ReadToEnd();
// Cleanup the streams and the response.
reader.Close();
dataStream.Close();
response.Close();
return responseFromServer;

}