#top {
background-color:#093;
height: 50px;
}
#footer {
background-color:#F30;
height: 50px;
clear:both;
}
#left {
background-color:#FF0;
height:400px;
width: 200px;
float:left;
}
#right{
background-color:#06F;
height: 400px;
width: 400px;
float:left;
}
#main {
background-color:#B7B7B7;
width: 600px;
border: 1px solid #666;
margin-right: auto;
}