My iphone 4 has a white? Black screen and it won't go aaway, how do I fix it?

My iphone 4 has a white? Black screen and it won't go aaway, how do I fix it?!

Before that screen popped up it kept restarting an restarting for hours! (just copy and paste the link to open it)

That doesn't look good. Unfortunately, I doubt you can do much. It could be a bad LCD, bad connection between the LCD and logic board, or bad logic board.

Personally, I'd sell the phone for parts and buy a newer one. Since it kept restarting, it could probably have more problems.