With xara premium web designer, how do get content of the web page centered on the screen, like e.g. this web page
http://dianev.com/web-design-help/we...e-content.html

The background fills up the entire width of the web browser but the main content is always centered in the web browser, no matter the width of the window. Is all the stuff in the middle contained in a frame or something?

TIA