Is there some sort of LeaveFullscreenEvent?

I have a game that runs on AIR, which lets you use the keyboard in fullscreen mode. When the user reverts back to normal viewing mode (by hitting Escape), a lot of things about the game suddenly change, and need to be fixed. I have a function that handles this, but it needs to respond to an event that occurs when the user leaves fullscreen.

I could listen to the keyboard, and check to see if the latest key hit was the Escape key. But my game has a lot of keyboard input, and I believe this might be slowing it down.

Is there just an event that is dispatched when Flash leaves fullscreen?