Excel-based application copyright issues

If I write an application in Excel that has commercial value, and I intend to sell it, where do I stand on the copyright issue?

I assume I automatically have the copyright on the application, because I wrote it.

But what happens if someone steals the code, or just puts their name on the app., and then sells it for their own profit?

In other words......even though I have copyright on the app., how do I prove this? Do I need to register it somewhere or something?

What do you guys normally do?

Cheers
-Rob

You can copyright here in the us for a nominal fee. Go to http://copyright.gov/ for the application form
and application process.

You can also TradeMark the app too. Checkout
http://www.uspto.gov/web/trademarks/workflow/start.htm

Mmm, I'm from the UK though. Not sure we have anything like that here.

Anyone else know if we do? :confused:

-Rob

Oh, sorry. I didnt realize that you were from the uk. Thought your from the usa for some reason? :blush:
Maybe it would be good to get an idea for protecting your app in the uk if you can find the right office to
do something similar.