いつも一番下に表示

* {
  margin:0;
  padding:0;
}
html, body {
  height: 100%; 
}
body{
  height:100%;
  position: relative; 
}
html>body  {
  height: auto; 
  min-height: 100%;
}  
/* footerのbgとheightをそろえる*/
#empty {
  height:120px;
}
#footer {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height:120px;
  background:transparent url(hoge.jpg) left bottom repeat-x;
}