Automatic windows authentication login

[Steve]

Hi

I have 2 intranet sites: Intranet_1 and Intranet_2 both secured using
integrated windows authentication in IIS. Using ASP.NET, is there a way to
allow a user logged into Intranet_1 to access Intranet_2 using a guest
account without IE prompting for the user name and password (for
Intranet_2)? In other words, I would like all users of Intranet_1 to have
automatic access to Intranet_2 but only with a special guest account. This
guest account info will be hardcoded into the asp.net code of Intranet_1.
Also, I cannot change any code or settings on Intranet_2.

Hope that made sense =) Any help or comments will greatly be appreciated.
Thanks.

Steve