We have a MVC application that authenticates users through forms authentication. Now we were able to add SSO authentication through ADFS 2.1 forms authentication.
When a user fills the application username field with an AD that is supposed to login through SSO, it's redirected to the ADFS login page to fill username and password to authenticate to the application.
All this is working fine. What we want to achieve now is to autofill the ADFS username field with the content from the application username field so that the user doesn't need to write the username twice.