.left-col {
float: left;
width: 620px;
margin-right: 20px;
margin-left: 10px;
}
.right-col {
float: left;
width: 300px;
margin: 0;
margin-right: 10px;
}

.left-col-top,
.left-col-middle,
.left-col-bottom {
float: left;
clear: both;
position: relative;
width: 620px;
}