#container {
  position: relative;
  background-color: #DDD;
}

#column-left {
  position: absolute;
  top: 0px;
  left: 0px;
  bottom: 0px;
  width: 20%;
  overflow: auto;
  background-color: #009900;
}

#column-mid {
  margin-left: 20%;
  width: 60%;
  background-color: #990000;
  padding: 1px 0;
}

#column-right {
  position: absolute;
  top: 0px;
  right: 0px;
  bottom: 0px;
  width: 20%;
  overflow: auto;
  background-color: #000099;
}

#column-right a {
  display: block;
}