I've had a LG Chocolate Touch for almost a year now, but recently (in the past 2 months), the touch screen hasn't been working. I can't access any of the features, but once in a while the screen will work for 5 minutes or so. The phone hasn't come into contact with water, nor has it been dropped, so I don't know why it's not functional. What could be wrong with it? Help is greatly appreciated!