Moving a window to the side doesn't resize it on the inside of multiple monitors

You know how in Windows 8 when you move a window to the side it will position the window so it takes up half the screen? The two monitor display I am using doesn't do that on the inside. So if I do it on the outside of the right monitor and the outside of the left monitor it works, but not in the middle. Is there a way to get it to work there, too?