Authentication Q - Cant use basic or windows

Hi,

I'm having problems with authentication.
I have a set of users that are allowed to use a webpage. They are in
domain A.
My goal is to get the username of these users and then check them
against my list.

The webpage is hosted under a username in domain B.
I cannot change any settings on the domains.

This means that i cant use windows authentication because of the
different domains.

I've tried to use basic authentication, but then a secondary function
that the webpage fires off doesnt work for some reason (i havent found
out why because i cant debug in my VS under basic auth!).

Is there anyway else to do it?
At the moment the authentication is set to anonymous but the username
is set to the same username the webpage is hosted under.

Thanks

.

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