iphone 4s reacts without touching screen

Hi,

The last week my black iPhone 4S 32Gb has begun to react very weird.

The keyboard reacts without me touching the screen, when I press ex. Safari then "Message" on the right reacts instead.

I cannot scroll without problems.

I've changed the front screen without any luck. I've made a soft reset and a hard reset without any luck. And now I'm getting a bit frustrated.

The phone was accidentally in the washing machine last year in March, but the problem with the screen first started last week, so I don't think that has anything to do with that. After the washing machine accident the proximity sensor hasn't worked.

Do anybody have any ideas on what I can do, besides buying a new phone?

Regards,

Lars Hansen