IPhone 4 stuck on blank white screen?

I opened Safari on my iPhone 4G this morning and nothing loaded, it's stuck on a blank white screen. I can see the black bar at the top that tells me I'm connected to the internet and the battery, but the rest of the screen is plain white. I have the assistive touch dot on because the lock button is jammed, and I can still go into its little menu, but when I press the home button (either on the menu or on my actual phone) nothing happens. I've been trying to turn it off but, again, the lock/power button is jammed, and it hasn't been working. I read that you can hold down "lock screen" in the assistive touch menu, but when I do that nothing happens either. I plugged it into the wall and into iTunes on my computer, still nothing.

When I leave it idle, it's doesn't turn off. The screen gets dark, but it's still on, I guess it's just the back-light that turns off? My only idea is to wait for the battery to die and then charge it and hope it goes back to normal.

Any advice would be much appreciated!

Try to hold the power button and the home button and then when it turns off let go of it.

please help asap
my iphone 4 is stuck on a grey screen with a white line going through it i cant press my lock button or home button they dont do anything ive tried everything and it just wont work!