Custom Authentication 3.5.5

[ispirtraian]

Hello,

I have enabled security in Websphere 3.5.5 to authenticate the access to resources. But I want to use a custom HTML login form instead of browser window when Basic Challenge Type is enabled.
So I thought that the answer to problem is the Custom Authentication Challenge Type. So I have defined the Login URL and the ReLogin URL (some test HTML pages).
But even with the Custom Authentication Challenge Type enabled I still get that login window from the browser.
I want to know if anyone successfully used the Custom Authentication Challenge, and what really does it means. It is a simple HTML form and IBM provides some specification(I didn't find anything)? or I do have to provide also the authentication mechanism? - I didn't understand this

Any help in this issue, would be appreciated

Thanks,
Traian