C / C++ / MFC

void CEditDlg::OnBnClickedAdvanced()
{
	static bool m_bExpand = false; 
	if (rcLarge.IsRectNull())
	{
		// Large window 
		GetWindowRect(rcLarge); 

		// Small window 
		CWnd* pWndDivider = GetDlgItem (IDC_DIVIDER); 
		pWndDivider->GetWindowRect (rcDivider); 

		rcSmall = rcLarge; 
                // Small windos cuts off at the divider
		rcSmall.bottom = rcDivider.top; 
		//Init the controls for re-sizing
		InitResizerLarge();
	}

	if(m_bExpand) 
	{ 
		SetWindowPos(NULL, 0, 0, rcLarge.Width(), rcLarge.Height(), SWP_NOMOVE | SWP_NOZORDER); 
		m_origSize = CPoint(rcLarge.Width(), rcLarge.Height());
		m_bExpand = false; 
		m_cAdvancedButton.SetWindowText("Hide Details");
	} 
	else 
	{ 
		SetWindowPos(NULL, 0, 0, rcSmall.Width(), rcSmall.Height(), SWP_NOMOVE | SWP_NOZORDER); 
		m_origSize = CPoint(rcSmall.Width(), rcSmall.Height());
		m_bExpand = true; 
		m_cAdvancedButton.SetWindowText("More Details");
	}
}