Hola...
Prueba esto, a ver si te sirve. Cópialo en un html limpio:
Código HTML:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Tres columnas</title>
<style type="text/css">
html, body {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #000;
font-family: Arial, Helvetica, sans-serif;
font-size: 13px;
}
#caja {
width: 960px;
height: 100%;
margin: auto;
background-color:#ffc;
}
#izquierdo {
width: 200px;
height: 100%;
background-color: #999;
float:left;
}
#central{
width: 560px;
height: 100%;
float: left;
background-color: #fff;
overflow: auto;
}
#derecho {
width: 200px;
height: 100%;
background-color: #999;
float:right;
}
p {
line-height: 100px; /* sólo para probar */
padding: 8px;
}
</style>
</head>
<body>
<div id="caja">
<div id="izquierdo"><p>Izquierdo</p></div>
<div id="central">
<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p>
<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p>
<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p>
<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p>
<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</p>
</div>
<div id="derecho"><p>Derecho</p></div>
</div>
</body>
</html> Bye