title: Read a XML (from a string) and get some fields - Problems reading XML
body: <p>I have this XML (stored in a C# string called <code>myXML</code>)</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-16"?&gt;
  &lt;myDataz xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt;
    &lt;listS&gt;
      &lt;sog&gt;
        &lt;field1&gt;123&lt;/field1&gt;
        &lt;field2&gt;a&lt;/field2&gt;
        &lt;field3&gt;b&lt;/field3&gt;
      &lt;/sog&gt;
      &lt;sog&gt;
        &lt;field1&gt;456&lt;/field1&gt;
        &lt;field2&gt;c&lt;/field2&gt;
        &lt;field3&gt;d&lt;/field3&gt;
      &lt;/sog&gt;
    &lt;/listS&gt;
  &lt;/myDataz&gt;
  </code></pre>
  
  <p>and I'd like to browse all <code>&lt;sog&gt;</code> elements. For each of them, I'd like to print the child <code>&lt;field1&gt;</code>.</p>
  
  <p>So this is my code :</p>
  
  <pre><code>XmlDocument xmlDoc = new XmlDocument();
  string myXML = "&lt;?xml version=\"1.0\" encoding=\"utf-16\"?&gt;&lt;myDataz xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\"&gt;&lt;listS&gt;&lt;sog&gt;&lt;field1&gt;123&lt;/field1&gt;&lt;field2&gt;a&lt;/field2&gt;&lt;field3&gt;b&lt;/field3&gt;&lt;/sog&gt;&lt;sog&gt;&lt;field1&gt;456&lt;/field1&gt;&lt;field2&gt;c&lt;/field2&gt;&lt;field3&gt;d&lt;/field3&gt;&lt;/sog&gt;&lt;/listS&gt;&lt;/myDataz&gt;"
  xmlDoc.Load(myXML);
  XmlNodeList parentNode = xmlDoc.GetElementsByTagName("listS");
  foreach (XmlNode childrenNode in parentNode)
  {
      HttpContext.Current.Response.Write(childrenNode.SelectSingleNode("//field1").Value);
  }
  </code></pre>
  
  <p>but seems I can't read a string as XML? I get <code>System.ArgumentException</code></p>