Closing the vertical toggle navigation menu?

I have a responsive design rule that is set to show the toggled vertical menu. While the menu itself is fine, I want to be able to allow for the menu to close if the user touches OFF the menu (i.e, not hitting the menu button again, or clicking on a child page link). In the attachment, if the user clicks anywhere except for the menu, I want for it to close.

 Is this possible? Is there a "close" event that I can trigger on the menu? Thanks.