FormatMessageフォーマットGetLastErrorが取得したエラーコード

void FormatErrCodeMessage(LPCTSTR lpszFunction, DWORD dwErrorCode) 
{ 
  // Retrieve the system error message for the error code
  DWORD dwMaxTCharLen = 32000U;
  LPTSTR lpDisplayBuf = (LPTSTR)LocalAlloc(LPTR, dwMaxTCharLen*sizeof(TCHAR)); 

  LPTSTR lpMsgBuf = NULL;

  if(FormatMessage(
    FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, //dwFlags
    NULL, //lpSource
    dwErrorCode, //dwMessageId
    0, //GetUserDefaultLangID(),// MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),//dwLanguageId
    (LPTSTR)&lpMsgBuf, //lpBuffer
    0, //nSize
    NULL //Arguments
    ))
  {
    _stprintf_s(lpDisplayBuf, dwMaxTCharLen,
      TEXT("%s failed with error code(%lu)\r
:%s"), 
      lpszFunction, dwErrorCode, lpMsgBuf);
  }
  else
  {
    _stprintf_s(lpDisplayBuf, dwMaxTCharLen,
      TEXT("FormatMessage function failed with error %lu"),
      GetLastError());
  }

  if(lpDisplayBuf)
    MessageBox(NULL, lpDisplayBuf, TEXT("Error"), MB_OK); 

  if(lpMsgBuf)
    LocalFree(lpMsgBuf);
  if(lpDisplayBuf)
    LocalFree(lpDisplayBuf);

  //ExitProcess(dwErrorCode); 
}