<? xml version="1.0" encoding="utf-8" ?>
< users >
< user FirstName ="Tom" LastName ="Adams" Age ="23" />
< user FirstName ="Jhon" LastName ="Brams" Age ="17" />
< user FirstName ="Bill" LastName ="Smith" Age ="33" />
</ users >

The code prints out all the user nodes of the users node that have an age with a value greater than 17

// Read the xml from resource file

string xml = Resources.Users;
using (StringReader sr = new StringReader(xml))
{
XPathDocument document = new XPathDocument(sr);
XPathNavigator navigator = document.CreateNavigator();
XmlNamespaceManager ns = new XmlNamespaceManager(navigator.NameTable);

//Selects all the user nodes of the users node that
// have an age with a value greater than 17

XPathNodeIterator it = navigator.Select("/users/user[@Age>17]");
while (it.MoveNext())
{
// access the atributes
string firstName = it.Current.GetAttribute("FirstName", ns.DefaultNamespace);
string lastName = it.Current.GetAttribute("LastName", ns.DefaultNamespace);
// Print out
Console.WriteLine( "{0} {1}", firstName, lastName );
}
}