Custom Login/password webpage

I want to use authentification in my web server but with a custom login/password page.
When the values are submited i call a function to implement the authentification, but how?
can I use the same functions that rabbitweb uses or must I implement all the authentification control with cookies or something simialr?

I have been looking for information in some forums but nothing found.

Hello,

You can see the login implementation details from the Digi’s link below.
http://ftp1.digi.com/support/documentation/019-0144_G.pdf

This is TCP/IP volume 2.