webpopup android back button listener

I am new to using Corona but have been tasked with researching if there is a way to have a listener for a Android hardware back button for webpopups.  It seems like they might be possible with webviews but our app is already setup for webpopups.  The reason I am looking into intercepting is if I can intercept I would like to force a refresh on the page that the user has gone back to.

Thanks

Here is the documentation for Android hardware keys:

http://docs.coronalabs.com/api/event/key/index.html#TOC

Here is the documentation for Android hardware keys:

http://docs.coronalabs.com/api/event/key/index.html#TOC