XElement customer = XElement.Load(@"..\..\customer.xml");

// Tento pkaz vybr prvn element address, podzen elementu addresses.
XElement firstAddress =
	(customer.Descendants("addresses").Elements("address")).First();

firstAddress.AddAfterSelf(
new XElement("address",
new XAttribute("type", "IT-blog"),
	"http://blogs.devleap.com/"),
new XElement("address",
new XAttribute("type", "US-blog"),
	"http://weblogs.asp.net/PaoloPia/"));
