Iphone 4 screen isn't touch sensitive

I have an iPhone 4s. I'm a mechanic, so it gets dropped a lot, the screen is busted pretty bad, but it still worked great, well the other day I went outside to help my mom find her dog that got out during a storm, it was raining pretty bad, I came back inside and pulled my phone out of my pocket and texted someone, got on Facebook, set it down, came back a few minutes later, tried to unlock it and it slid over about halfway, then I tried again and the little menu, that comes up when you slide from bottom to top with newest update, came up when I slid sideways to unlock, slid it back down, tried unlocking again, wouldn't do anything. Siri still works, volume works, but the screen won't work when you touch it, not even to fast forward or pause music. Can anyone help? I put it in a bag of rice overnight to get moisture out in case that was the problem, reset it using home and lock button since I couldnt turn it off by holding the lock button and sliding. Anymore ideas?

Change the screen.