Weblogic and Siteminder Authentication Problem

HI I have an application deployed on Weblogic 8.1 SP4  and for Authentication purpose we are using Site minder. I have deployed the application and when i send a request for login page iam getting the following error.

Error 401--Unauthorized xxx
From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:
10.4.2 401 Unauthorized
The request requires user authentication. The response MUST include a WWW-Authenticate header field (section 14.46) containing a challenge applicable to the requested resource. The client MAY repeat the request with a suitable Authorization header field (section 14.8). If the request already included Authorization credentials, then the 401 response indicates that authorization has been refused for those credentials. If the 401 response contains the same challenge as the prior response, and the user agent has already attempted authentication at least once, then the user SHOULD be presented the entity that was given in the response, since that entity MAY include relevant diagnostic information. HTTP access authentication is explained in section 11.

I dint understand what the problem was.
Please help.

Thanks,
Rave