What's happen to my keyboard

Hello, I asked this question within an older topic of this website, but I receive the advice to ask it as a new question.

so here is my problem

I put coffee without milk or sugar on my unibody mac 13'' 2 days before. I let it dry all night long, after cleaning what I can clean, but maybe I didn't wait enough...

Yesterday, the computer was okay, it works well, excepted some sticky keys on the keyboard. and with the time running, after two hours is was several keys that are not working anymore. So I take out some of the keys to clean it, but they are clean! And even, when I press on the plastik button, corresponding to the key, nothing happen.

so I don't know?? Now the computer is shut down and I will wait. But I'm worried about it. Do you have an idea of why the keys break only after a while?

Sorry for my english, I'm working on it =)