In infopath,I can show the current user name and Domain  name in textbox  
through review ,but   it  can not see the result in .xml.

code:
function XDocument::OnLoad(eventObj)
{
  var objNetwork = new ActiveXObject("WScript.network");

    //Retrieve the UserName and write it into the my:UserName field
    XDocument.DOM.selectSingleNode("//my:UserName").text
    =objNetwork.UserName;

    //Retrieve the UserDomain and write it into the my:UserDomain field
    XDocument.DOM.selectSingleNode
    ("/my:myFields/my:UserDomain").text
    = objNetwork.UserDomain;
}

requst help!!!