Add check box in VC++

2D stuff needs to be shown to UL and a simple 3D is needed too. I put a check box there (3D) temporarily.
Add Variables (three_D)... Add Event Handler...
void CDlgOglDlg::OnBnClicked3dmodel()
{
UpdateData(TRUE);
if(three_D == TRUE)
{
m_pclGlView->threeD = 1;
}
else
{
m_pclGlView->threeD = 0;
}
}
threeD is defined in another Class.