Hitting keyboard keys then another letter appears on the screen

I am using a HP keyboard at first it was working well and then one time i spilled a coffee in it. after i turned on the computer and start working in my documents i found out that the keyboard is not following the right letters when i hit a key instead the other letter appears on the screen(example: when i hit the key Z, letter U appears on the screen).
Can anyone please help me with my problem?
