what's wrong in this?(IXMLDOM)

[fenery]

// ListDirToXML.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#import "msxml3.dll" named_guids
using namespace std;
using namespace MSXML2;

int main(int argc, char* argv[])
{
MSXML2::IXMLDOMDocument *pXMLDomDoc=NULL;
HRESULT hr;

CoInitialize(NULL);

hr=CoCreateInstance(
__uuidof(DOMDocument30),
NULL,
CLSCTX_INPROC_SERVER,
__uuidof(IXMLDOMDocument),
(void**)&pXMLDomDoc);
if(FAILED(hr))
{
cout<<"CoCreateInstance Failed"<<endl;
CoUninitialize();
return 0;

}

pXMLDomDoc->put_async(VARIANT_FALSE);
pXMLDomDoc->preserveWhiteSpace=VARIANT_TRUE;


pXMLDomDoc->loadXML(_T("<root></root>"));


MSXML2::IXMLDOMElement *pXmlRoot=NULL;
pXmlRoot=pXMLDomDoc->GetdocumentElement(); //wrong?

MSXML2::IXMLDOMElement *pXmlA=NULL;
pXmlA=pXMLDomDoc->createElement(_T("A")); //wrong??
pXmlRoot->appendChild(pXmlA); //wrong???


pXMLDomDoc->save(_T("test.xml"));


CoUninitialize();
return 0;
}

I'm new in XMLDOM programing,waiting for your help.