Get the computer user name in a web application

I have a web application where forms authentication is used. The user names are the same that the ones used by the users in their computers, so they want the web app to be able to detect that user name so the app can log it the user automatically.

How can it be done? I mean, if I set the authentication mode to "Form" do I still get those credentials from IIS?

I know this can be done in several better ways than this, but I am interested in this particular way. As it is a small web app in an intranet with开发者_高级运维 a few users doesn't worth it a big architectural change. If it's possible, happy days, otherwise it will have to wait.

Cheers.

That cannot be done with Forms Authentication. Without prompting the client for credentials, there is no way to retrieve that information from the client's machine.

Windows auth cannot coexists with Forms auth, but it can coexists with Anonymous auth.

More info here: Windows authentication is not challenging browsers out of the domain