2005 Honda Accord LX 2.4L

So I have a 2005 Honda Accord LX 2.4L which I
purchased recently. It came with just one key and
the key was worn down some, but the buttons click
and everything, just no light when clicking on them.
I see the horn in the car and the person I bought it
from told me nothing about any problem with it.
So, I opened the key and replaced the battery and
voulahh, it lights up. Bad part, it doesnt do anythinf
to the car when I click on any of the buttons. So, I
want to know what I can do to make it actually
work. Is there a fuse I can replace to make it work
again or what? Thank You.