html,
body {
   margin:0;
   padding:0;
   height:100%;
}
#container {
   min-height:100%;
   position:relative;
}
#header {
   background:#ff0;
   padding:10px;
}
#body {
   padding:10px;
   padding-bottom:60px;   /* Height of the footer */
}
#footer {
   text-align:center;
   padding:30px;
   position:relative;
   bottom:100%;
   width:100%;
   height:60px;   /* Height of the footer */
   background:#202020;
}