Hola
Dani_, bienvenido al foro. Proba:
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=iso-8859-1" />
<title>Documento sin título</title>
<script language="Javascript">
function capa(Datos)
{
document.getElementById(Datos).style.visibility="Visible";
}
///////////////////////////////////////////////////////////
function ocultar(Datos){
document.getElementById(Datos).style.visibility="hidden";
}
///////////////////////////////////////////////////////////
</script>
<style type="text/css">
<!--
#Layer1 {
position:absolute;
left:1px;
top:1px;
width:150px;
height:100px;
z-index:100;
background-color: #330066;
border:5px;
border-color:#CCFF00;
border-style:double;
visibility: visible;
}
#Layer2 {
position:absolute;
left:1px;
top:112px;
width:150px;
height:470px;
z-index:100;
background-color: #0000FF;
border:5px;
border-color:#CCFF00;
border-style:double;
visibility: visible;
}
#Datos {
position:absolute;
left:163px;
top:1px;
width:1024px;
height:580px;
z-index:100;
background-color: #FFFF66;
border:5px;
border-color:#CCFF00;
border-style:double;
visibility: hidden;
}
#Libre {
position:absolute;
left:163px;
top:1px;
width:1024px;
height:580px;
z-index:200;
background-color: #FFFF66;
border:5px;
border-color:#CCFF00;
border-style:double;
visibility: hidden;
}
#Layer4 {
position:absolute;
left:100px;
top:0px;
width:903px;
height:590px;
z-index:100;
background-color: #999999;
visibility: visible;
}
.Estilo1 {font-family: Arial, Helvetica, sans-serif}
.Estilo2 {
color: #CCFF00;
font-weight: bold;
}
.Estilo3 {
font-size: 36px;
font-weight: bold;
}
.Estilo4 {color: #CCFF00; font-weight: bold; font-size: 24px; }
-->
</style>
</head>
<body>
<div class="Estilo1" id="Layer1">
<div align="center" class="Estilo2">Daniel </div>
</div>
<div id="Layer2">
<div align="center">
<p> </p>
<!-- ----------------------------------------------------------------------- -->
<p><a href="#" class="Estilo4" onclick="ocultar('Libre');capa('Datos')" >Datos</a></p>
<p><a href="#" class="Estilo4" onclick="ocultar('Datos');capa('Libre')" >Libre</a></p>
<!-- ----------------------------------------------------------------------- -->
</div>
</div>
<div id="Datos">Pagina Datos</div>
<div id="Libre">Pagina libre</div>
</body>
</html> Te marque donde hice los cambios