MVC3 - show processing message (not on an ajax call)

I have a link… target page will do some processing, create pdf and then will push it out as a file download.

If all goes well then the target page will not even display, user will only see a save as dialogue box.

How best can i provide a processing message with animated gif here? This is not an ajax call, simple link click…

simply use jquery blockUI ( until the file is ready