body {
  background-image: url(img/background.jpg);
}

div#main
{
  background-image: url(img/back_mid.jpg);
}

div#main div.main_head
{
  background-image: url(img/back_head.jpg);
}

div.foot{
  background-image: url(img/back_foot.jpg);
}

.main_mid_up{
  background-image: url(img/back_mid_head.jpg);
}

.main_mid_down{
  background-image: url(img/back_mid_foot.jpg);
}