Touchscreen won't work?

[Miaaa]

Hi, I've had my droid 3 or 4 months now. It's had an issue where it only would unlock if I slid it up and use that unlock screen. Suddenly, it won't unlock at all. I have to turn the phone off and then on to unlock it.

Any ways I can fix this? :s

 

[Miaaa]

Anyone? Please D: