how to parse xml , linq c#

i am trying to load the xml file as below and read the value for each element but the Result count always = Zero , below my xml example with code

1 ) My xml is :

<ROOT xmlns="authenticateUser">
<PARTYCODE></PARTYCODE>
<VRETCODE>10</VRETCODE>
<PRETCODE>10</PRETCODE>
<VRETERR>Incorrect user name or password entered.</VRETERR>
</ROOT>

2 ) My Code is :

 XDocument Doc = XDocument.Parse(strFileData);
                    var Result = (from Root in Doc.Descendants("ROOT")
                                  select new
                                  {
                                      PARTYCODE = Root.Element("PARTYCODE").Value ?? string.Empty,
                                      VRETCODE = Root.Element("VRETCODE").Value ?? string.Empty,
                                      PRETCODE = Root.Element("PRETCODE").Value ?? string.Empty,
                                      VRETERR = Root.Element("VRETERR").Value ?? string.Empty,
                                  }).ToList();