/****** Our approach *********/
body.responsev2 div.header {
    background-image: url(http://www.riotinto.com/response/images_structure/bg_header_RioTinto_response.jpg);
}
body.responsev2{
    background-image: url(http://www.riotinto.com/response/images_structure/bg_body_RioTinto_response.jpg);
}