what I want to do just is defusing request which want to get image and has not logon in(has no session).
I want to get image in excel,not show in ie!So how can I get it!

thank you!

The user is requesting some aspx page. On that page check if the user
has been authenticated. If yes then show\give him the image. else
redirect to the login page.

Once the USER has been logged in to the system, redirect him back to the Page he originally requested.

Hope this might help.
Thanks
Musa