SetRectRgn( childupdate , child->m_x , child->m_y , child->m_x + child->m_width , child->m_y + child->m_height ) ;
SectRgn( childupdate , updatergn , childupdate ) ;
OffsetRgn( childupdate , -child->m_x , -child->m_y ) ;
SetRectRgn( childupdate , child->m_x , child->m_y , child->m_x + child->m_width , child->m_y + child->m_height ) ;
SectRgn( childupdate , updatergn , childupdate ) ;
OffsetRgn( childupdate , -child->m_x , -child->m_y ) ;