IE7 form authentication after ntlm authentication failed

Question

I have a problem with authentication:

• Users that have valid domain credentials are logined using NTLM authentication (i send "WWW-Authenticate: NTLM " header and 401 status in my jsp filter. Then IE authenticate user using NTLM and everything is fine.

• I have other users (connected to lan with their own computers) and they can't logged using NTLM. I created a form where they can enter their credentials and log in.

  I want to create mixed-authentication. I add code then redirects user to form login page when his NTLM authentication fails. But when user enter credentials in form redirected after NTLM-auth check, the post data from form doesn't send to jsp page. Instead of post data i see header "Authorization NTLM bla-bla-bla".

  Any proposals how I can create mixed-authentication?