What's up with COMBOBOXINFO

I would like to get the handle to the edit control of a combo box with the style CBS_DROPDOWN. Let me say that I am using VC 6.0 and this combo box is a CComboBox added to a dialog with the dialog editor.
My attempt was to use
pCB is a pointer to the combo box
COMBOBOXINFO CBInfo;
::GetComboBoxInfo(pCB->m_Hwnd, &CBInfo);
CBInfo.hwndItem is the handle to the edit box.

Problem is that I get errors saying
COMBOBOXINFO indeclared identifier
GetComboBoxInfo is not a member of the global namespace

As far as I can tell the include needed is Windows.h so I do not know what is wrong here?

Just out of curiosity...which operating system do you use?

The structure as well as the function are only available on Windows 98 or higher / Windows NT 4.0 SP6 or higher...

Hi, thanks for the reply. I am using both W2K with SP 3 and visual studio SP6 and WinXP SP1 which has a learning addition of VC and I have not installed any service packs.

I also tried removing VC_EXTRALEAN to no avail.

It seems I have an outdated version of the SDK