body {background-color:black; color: white;}

div#wrapper { position: relative; width: 800px;}
div#left { float: left; width: 200px; border: thick solid green; background:yellow;}
div#right { float: right; width: 200px; border: thin solid blue;}
div#center{ float: left; width: 400px; border: thin solid red;
  left: 200px; top: 0em;}
div#footer{ clear:both; border: thin solid yellow; width:100%;}