“Thinking” Page Plugin

Hey,

I’m building a site that makes a lot of calculations, sometimes it take 5 sec, some times it take 30 sec.
I want that the user will press the “submit” button, will go to a page that says:
“Doing Something really complicated.. please wait” and then when the page is ready it will redirect him to the answer page.
Is there a plugin ready for such feature?

Thanks