XML Namespace prefix problem

[rahulrv]

Hi,
I have an xml which looks like this:

<Events>
<Event xmlns="[URL]http://abc.com[/URL]">
 <System>
  <Name ="abc" />
</System>
 <Manager>
  <Name ="abc1" />
</System>
</Event>
</Events>

I use the following code to obtain the System node and it fails

XmlDocument document = new XmlDocument();
document.Load("c:\\results.xml");
XmlNodeList tmp1 = document.GetElementsByTagName("Event");
foreach (XmlNode k in tmp1)
{
XmlNode a = k.SelectSingleNode("System");

a always returns NULL
if I add a prefix to the URI, or remove the namespace URI from the results.xml, then it works, however, this is the XML i need to parse, any ideas.

if (a != null)

What am I doing wrong?