In the OnPaint funtion under else add this
else
{
CPaintDC dc(this);
CRect rect;
GetClientRect(&rect);
BITMAP bmp;
HBITMAP hBmp = ::LoadBitmap(::AfxGetInstanceHandle(), MAKEINTRESOURCE(IDB_BITMAP2));
::GetObject(hBmp, sizeof(bmp), &bmp);
HDC hDC = ::CreateCompatibleDC(NULL);
SelectObject(hDC, hBmp);
::BitBlt(dc.m_hDC, 0, 0, rect.Width(), rect.Height(), hDC, 0, 0, SRCCOPY);
CDialog::OnPaint();
}