#header {
  background: #0f0;
  top: 0px;
  left: 0px;
  width: 400px;
  height: 100px;
}
#leftcol {
  background: #f00;
  top: 100px;
  left: 0px;
  width: 150px;
  height: 500px;
}
#rightcol {
  background: #f00;
  left: 650px;
  top: 100px;
  width: 150px;
  height: 500px;
}
#content {
  background: #fff;
  top: 100px;
left: 150px;
  width: 150px;
  height: 500px;
}
#footer {
  background: #0f0;
  top: 500px;
  left: 0px;
  width: 400px;
  height: 100px;
}