ASP.NET passing along Windows Authentication credentials

I've got an ASP.NET web application which uses Windows Authentication. This application needs to connect to another ASP.NET web service (which also uses Windows Authentication) and use the same credent开发者_开发问答ials that it received from the user's browser. Can this be done and how?

---

I don't believe you can do this without Kerberos Authentication. You can't delegate credentials to another system.

I think this will start to set you on the right track.