WHITE SCREEN ON IPHONE WON'T GO AWAY

I tried going on Safari and a white loading screen came up (as usual). But this time it won't go away. If I push the home button, nothing will happen. If I push the off button, nothing will happen. I've tried completely turning it off and still nothing will happen. It's not completely frozen because I'm able to move the screen up and down, but that's all. And it won't shut off by itself either. Please tell me how to get it back!
I have an iPhone 4 btw.

Simultaneously press the lock and home button until it is a black screen. Power it back on holding the power button.