Detect if mouse has left or entered the browser window

Hi

I'm using EA v2014.1.1

I need to hide a symbol when the mouse leaves the browser window and show the symbol again when the mouse enters the browser window.

Then when the mouse has entered the browser window, if it doesn't move for a few seconds, the symbol should hide again.

Has anyone done anything like this?

I'm struggling because I am unsure how to target the window or viewport.

Thanks

A