>Hi,
>
>Thought this would be simple, but ....
>
>I have a ASP.NET web form for which IIS requires Windows authentication. From the form I need to call a web service using the same identity as that provided to access the form.
>
>How do I do that,
>TIA,
>Viv

Viv,

You should be able to pass a WindowsPrincipal object to the Web Service, then attach that to the thread of the Web Service. I haven't tried it, but there's nothing in the docs to indicate that it wouldn't work.

See WindowsPrincipal, WindowsIdentity, and Thread.CurrentPrincipal in the help to get started.