Changing the login page

We currently use several systems using a single sign on which is not generated from the Windows Authenticated session.

A user will be using a windows session logged in as a generic user. They will then login to our intranet using their individual username/password, and that is what we use to generate our single sign on utility (which is already in place and works fine).

However, we need to change the SDP (Version 7 build 7009) login page in order to insert our code for the single signon.

Does anyone know which files are needed to be changed in order for us to insert some code into the header section of the login page please?

I have done a quick search in windows and found nothing.

Also, if anyone knows which file the PreLogout function is in (basically the function that is run when you click logout)

Cheers

Sinc