Keyboard not working properly

I have a Dell Inspiron 600m Laptop. From a couple of days,few keys are not working. Letter g , digit 5, ctrl key are not responding.And all of a sudden letter g is continuously appearing on the window automatically. Should i need to replace the keyboard or can i troubleshoot it? My Keyboard is clean without any dust.Few days ago small amount of water has spilt on the keyboard.Please help me in resolving this issue.