Using XML in Flash as3/cs4

So I’ve been following the tutorial on this site http://www.kirupa.com/developer/flashcs3/using_xml_as3_pg3.htm

I’m on page 3 where it starts to try and drill down to get specific nodes of data, but as soon as I add any kind of extra node to the trace like

trace(bookInput.Book)

It just starts returning no information from the XML.

Is this because I’m trying to use CS4 instead of CS3 or is it something else?