My iPhone 4s Lock Button Is Broken and the Phone Just Turned Off?

I have a iPhone 4 which i've had for about a year and a half. A few months ago my Lock button on the top broke, even if I press really hard nothing happens. I turned on that Assist Button thing to lock it and it was all going well until today when my stupid junk iPhone decided to turn off on me.
Now the darn thing won't turn on. I've tried plugging it into the wall, nothing. Tried connecting it to my computer and iTunes won't even recognize it!

If any one has a clear answer, please reply!

Connect it to a computer or your iTunes.