Div css probleem

div#submenu {
float: left;
width: 160px;
background: #fff;
border-right: 3px solid #000;
border-top: 3px solid #000;
border-left: 3px solid #000;
border-bottom: 3px solid #000;
}
div#inhoud {
float: right;
width: 600px;
padding: 0 20px;
background: #fff;
border-right: 3px solid #000;
border-top: 3px solid #000;
border-left: 3px solid #000;
border-bottom: 3px solid #000;
}
div#copyright {
background: url(images/balk.png) repeat-x;
color: #000;
position: absolute;
width: 100%;
bottom: 0;
left: 0;
text-align: center;
}