Game communicating with HTML page

Hi guys

I know that you can get your game to communicate with the html page the game is sitting in, BUT is there a way for the game to communicate with another html page?

For example ...

Let's say I have an INDEX.HTML page with a thumbnail leading to my game page (GAME.HTML)

When I play the game and reach a certain level, I would like to change the thumbnail on INDEX.HTML

Is there anyway to do this?

Thank you heaps for any help on this