Pgtips and Brian,
Thanks for the quick help...although the book seemed to indicate that the append worked with a loaded file, the example didn't show that so I wasn't 100% sure.
Anyway, with your help I figured out my problem. With a new object, the appendedChild method was creating the root element. With the loaded file, I needed to create a node object that held the parentnode <custorders>, and then I was able to append the <order> element to the the parent.