My Iphone lock screen keyboard is not working?

I turned on my iphone 4S and went to type in the passcode but the keyboard will not work. It looks like i'm typing but the letters will not show up. I cant even make an emergency call. The buttons just will not work. Is there anyway i can get into my phone without having to restore?
please help me fix this!

Added (1). My screen still works. I can slide the slide to unlock button and when i click the buttons it looks like they are being clicked. But when i type the letters will not appear in the passcode area

Iphone screen repair want