Efficient HTML Div with hole in it

Question

Let me explain a bit more, I am trying to have a large area (full screen) with a fixed size hole in it. The hole will follow the mouse around the screen. Think of having a

Answer 1

1. Have one div which is twice as wide and twice as tall as the viewport.
2. Inside that, put your four divs to create the fixed-width hole in the middle.
3. In your javascript, make the outer div move around with the cursor, rather than resizing the four divs.