How can I make my Sony Ericsson Z550i mobile which fell into water?

I dropped my Sony Ericsson Z550i in water and i took it out as fast as possible. I switched OFF the mobile and removed the battery and made the mobile dry in HOT SUN. After an hour in curiousity, i put the battery and switched ON the mobile without the SIM card and it worked and asked me to insert the sim. i PUT THE sim AND SWITCHED on AGAIN, BUT IT DIDN'T WORK. IS THERE ANY WAY I CAN MAKE MY MOBILE WORK?

Richard
June 2008