I can't get a notification to close off of my iPhone?

My iPhone 4S had a notification pop up that said "Not Enough Storage" and the only options are to close it or go to settings, and whenever I press either, NOTHING happens. It won't go away. I can't do anything on my phone either because it won't go away. Please help! I understand what the notification means, it's just it won't go away! No matter how many times I press the close option or the settings option it doesn't do anything!

Reboot your iPhone just hold down the home button and the lock button for about 10-15 thn the iPhone will restart again. And tht should work.