Row of divs central align when user resizes browser window

[samslystone]

Hi all

http://www.livialima.com/test/index.html

I currently have two divs side by side when the user views the window at full screen. However, should the user resize the window or be viewing on a smaller monitor I would not only like the second div to drop down beneath the first (as it does now) but for them both to centrally align. Can this be done using CSS?

Any suggestions most welcome!

S