So I constantly do this - I go to hit "I have sent my cards" and click "I have received my cards" instead by mistake. So I hit "cancel" hoping that it will take me back a step, but that only tells the site not to update my inventory. So the trades look prematurely complete, and I've lost the chance to automatically update the inventory. Can you switch it to a Yes/No/Cancel option instead?

Sounds good. Will do.