how disable border of dialog?

I create dialog by invoke "ShowHTMLDialog":

SHOWHTMLDIALOGFN  *pfnShowHTMLDialog;

pfnShowHTMLDialog = (SHOWHTMLDIALOGFN*)GetProcAddress(m_hInstMSHTML, TEXT("ShowHTMLDialog"));

if (!pfnShowHTMLDialog) return -1;

//Now create a URL Moniker
IMoniker* pmk = NULL;
BSTR bstrURL = m_strURL.AllocSysString();
CreateURLMoniker(NULL, bstrURL, &pmk);
if (!pmk) return -1;

TCHAR* pchOptions = m_strOptions.IsEmpty() ? NULL : m_strOptions.GetBuffer(0);

//Now show the HTML Dialog
HRESULT hr = (*pfnShowHTMLDialog)(m_hWndParent, (IMoniker*)pmk, m_varArgs, (WCHAR*)pchOptions, m_varReturn);
if (FAILED(hr)) return -1;


but this dialog has title bar.

How disable it?
.