How I get data alphabatically from xml file in Listbox

Question

I want to set asending/desending order (name) in my listbox contains all name 

Here is my xml file

 <?xml version="1.0"?>
<phonebooklist>
  <pbdata>
    <name>Tanmay</name>
    <contact>1324569780</contact>
  </pbdata>
  <pbdata>
    <name>Ranjan</name>
    <contact>8956231447</contact>
  </pbdata>
  <pbdata>
    <name>Tamojit</name>
    <contact>342352</contact>
  </pbdata>
  <pbdata>
    <name>deba</name>
    <contact>666666</contact>
  </pbdata>
</phonebooklist>

I can get name by:

 XmlReader xr = XmlReader.Create("test.xml");
            while (xr.Read())
            {
                if (xr.NodeType == XmlNodeType.Element && xr.Name == "name")
                    listBox1.Items.Add(xr.ReadElementString());
                else
                    xr.Read();
            }

but how i set it alphabetically?

Thank you in advance! :)