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/* Word Document (*.doc)  : {00020906-0000-0000-C000-000000000046} */ 
static const GUID CLSID_WORD = 
{ 0x00020906, 0x0, 0x0, { 0xC0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x46 }}; 

/* Excel Worksheet (*.xls) : {00020820-0000-0000-C000-000000000046} */ 
static const GUID CLSID_EXCEL = 
{ 0x00020820, 0x0, 0x0, { 0xC0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x46 }}; 

/* PPT Presentation (*.ppt) : {64818D10-4F9B-11CF-86EA-00AA00B929E8} */ 
static const GUID CLSID_PPT = 
{ 0x64818D10, 0x4F9B, 0x11CF, { 0x86, 0xEA, 0x0, 0xAA, 0x0, 0xB9, 0x29, 0xE8 }}; 


void IDFileType(BSTR bstrFile) 
{ 
  HRESULT    hr = S_OK; 
  IStorage*  pStg = NULL; 
  STATSTG    ST; 
  char*      pszApp; 

  if(NULL == bstrFile) return; 

  /* Open Compound Document for READ Access... */ 
  hr = StgOpenStorage(bstrFile, NULL, STGM_READ | STGM_SHARE_EXCLUSIVE, NULL, 0, &pStg); 

  if(FAILED(hr)) { 
    MessageBox(NULL, "Not a valid Compound Document!", "Error", MB_SETFOREGROUND); 
    return; 
  } 

  ZeroMemory(&ST, sizeof(STATSTG)); 

  /* Get Storage Stats and check CLSID against known values... */ 
  hr = pStg->Stat(&ST, STATFLAG_NONAME); 
  if(SUCCEEDED(hr)) { 
    if (ST.clsid == CLSID_WORD) 
      pszApp = "Word Application"; 
    else if (ST.clsid == CLSID_EXCEL) 
      pszApp = "Excel Application"; 
    else if (ST.clsid == CLSID_PPT) 
      pszApp = "PowerPoint Application"; 
    else 
      pszApp = "Unknown Application"; 

    SetWindowText(GetDlgItem(g_hWnd, IDC_APPNAME), pszApp); 
  } 

  /* Must release IStorage interface to free document!! */ 
  pStg->Release();