My Iphone 4 has a blank screen- Help!

So, i was listening to Spotify on my Verizon Iphone 4 and then i pressed pause and then the home button and then all of a sudden my screen went white. I can still see the time, battery and i can also still see that i have 3G and full bars. It won't let me lock it or turn it off either! But, it will still allow me to 'screen shot.' Does anyone know what i can do to fix it? I don't have warranty and when i plug it into my computer, my account won't show up on Itunes (it has always done that)

Added (1). OMG. Thanks guys! That worked! I am so happy now lol (:

Dfu mode? Hold power and home button until it shuts off maybe that will help

Try holding the Power and the Home buttons at the same time(for 3-4 seconds) until your screen flashes and your iPhone should reset itself(not like resetting contacts or notes it just shut everything off and turns it back on)