title: XML append data to the exsisting file in c#
body: <p>am new to XML,so need some help on XML.The below is the XML file,need to append data to the exsisting XML file.
      If it is new  node need to add to the exsisting XML file without losing the data.And if it is new database node need to add the new database node to the exsisting document.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
  &lt;servers&gt;  
    &lt;server serverid="server1" name="test" address="test"&gt;
      &lt;port asset="test" portid ="port1" portname="test" stopReq="N" serverid="server1" name="test" url="test"&gt;&lt;/port&gt;    
    &lt;/server&gt;
  
    &lt;server serverid="server2" name="test" address="test"&gt;
      &lt;port asset="test" portid ="test" portname="test" stopReq="N" serverid="server2" name="test" url="test"&gt;&lt;/port&gt;
    &lt;/server&gt;
  
    &lt;server serverid="server5" name="test" address="test"&gt;
      &lt;port asset="test" portid ="port31" portname="test" stopReq="Y" serverid="server5" name="test" url="test"&gt;&lt;/port&gt;
      &lt;port asset="test" portid ="port110" portname="test" stopReq="Y" serverid="server5" name="test" url="test"&gt;&lt;/port&gt;
      &lt;port asset="DART" portid ="port111" portname="test" stopReq="Y" serverid="server5" name="test" url="test"&gt;&lt;/port&gt;
    &lt;/server&gt;
  
  
  &lt;database dbname="test" server="test" UID="test" PWD="test" dbType="test" name="test"&gt;&lt;/database&gt;
  &lt;database dbname="test" server="test" UID="test" PWD="test" dbType="test" name="test"&gt;&lt;/database&gt;
  
  
  &lt;/servers&gt; 
  </code></pre>