div#header {
border: 0px solid green;
width: 700px;
height: 135px;
padding: 0 100px;
position: relative;
left: 50%;
margin-left: -450px;
}

div#nav {
border: 0px solid #000;
width: 700px;
height: 40px;
position: relative;
left: 50%;
margin-left: -350px;
}

div#subnav {
border: 0px solid #000;
width: 700px;
height: 25px;
margin-top: -15px;
position: relative;
left: 50%;
margin-left: -350px;
}

div#content {
border: 0px solid red;
width: 700px;
height: auto;
padding: 0 100px;
position: relative;
left: 50%;
margin-left: -450px;
}

div#column_left {
width: 340px;
float: left;
margin-right: 20px;
}

div#column_right {
width: 340px;
float: right;
}

div#footer {
border: 0px solid green;
width: 700px;
height: 40px;
position: relative;
left: 50%;
margin-left: -350px;
}