some keys don't work after water spilling

Hi, I spilled water on my keyboard, and my friend didn't know I had spilled water, so a few hours later he started using the computer for a few hours.

The next morning I found some of my keys not functioning (all my numbers, volume, backspace, some letters). When I clicked on the flag icon in the upper right corner, then clicked "show keyboard viewer", I clicked on the nonfunctioning keys, and they didn't light up.

I've kept the computer off with the battery out for three days now, and after turning it back on again, the keys still don't work.

What is my problem, and what can I do to fix it?

Thank you!