Returns the root of the document that contains this node.
Set objXMLDOMDocument = oXMLDOMNode.ownerDocument
HRESULT get_ownerDocument( IXMLDOMDocument **DOMDocument);
This method indicates the document to which this node belongs.
All nodes are created in the context of a document, and the ownerDocument method is maintained until the node is added to another document. For a node removed from a document, this method indicates the document in which the node was last included.