Integrated Directory Security

I have a site that uses Integrated Windows Auth, the problem I am
trying to solve is, if I have a user that doesnt have access to the
site, I would prefer that the site just take him/her to the 401.1
page, instead of brining up the username/password dialog box, the
default behavior seems to be you have to hit cancel in order for the
user to realize they are not authorized. I would like them to see the
page since I have a customized page explaining what they should do.