#header{
 background:darkred;
 width:1200px;
 height:100px;
 }
#menu{
 position:fixed;
 background:white;
 width:200px;
 height:700px;
 }
#content{
 position:absolute;
 left:230px;
 top:230px;
 background:white;
 width:900px;
 height:900px;
 }
#footer{
 position:relative;
 top:1380px;
 background:#666;
 width:1200px;
 height:85px;
 }
body{
 margin:5px;
}