My Nikon D90's trash button is stuck, what can I do?

Last summer, my cousin accidentally kicked sand (I know, eep) at me and it got all over my camera. I cleaned it as best as I could, and everything was working well, except the trash button. But over time it went away. Well it's back now, and when I press the button once, it goes in and stays in, which then causes none of the buttons to work on the back of the camera. I have to turn it off, and pry the button out for any of those buttons actions to show up.
What can I do?

Take it to the store and change it

You really only have two choices.

1. You can simply not use the Trash button, and only delete photos after downloading them to your computer. Inconvenient, but very doable. Buy extra SD memory cards, as they're fairly inexpensive.

2. Your camera needs a professional cleaning. Obviously there's grit or other gunk that's gotten behind the trash button, and who-knows where else. Take it to your local camera shop (NOT Best Buy or Walmart, please) and they should be able to give you a free estimate for a professional cleaning. However, you may need some disassembly, so they can full inspect for other damage. After all, if this Trash button problem didn't show up for several months, what else will happen later? I'd strongly suggest you find an Authorized Nikon Service Center, as they have the parts, expertise, and experience.
http://www.nikonusa.com/...-List.page