Private Sub OnTopCheck_Click()
    If OnTopCheck.Value = vbChecked Then
        SetWindowPos MDIForm1.hwnd, _
            HWND_TOPMOST, 0, 0, 0, 0, _
            SWP_NOMOVE + SWP_NOSIZE
    Else
        SetWindowPos MDIForm1.hwnd, _
            HWND_NOTOPMOST, 0, 0, 0, 0, _
            SWP_NOMOVE + SWP_NOSIZE
    End If
End Sub