Aupa. Prueba este código:
Código:
<html>
<head>
<title>7</title>
<style>
#divContenedor { background-color: red;
position: relative;
width: 500px;
padding-bottom: 20px;
}
#divContenido { background-color: yellow;
width: 200px;
overflow: auto;
max-height: 180px;
height:expression(
this.scrollHeight > 180? "180px" : "auto" );
position: relative;
}
</style>
</head>
<body>
<div id="divContenedor">
<div id="divContenido">aaaaa<br />
<br />
aaaaa<br />
aaaaa<br />
<br />
aaaaa<br />
aaaaa<br />
<br />
aaaaa<br />
aaaaa<br />
<br />
aaaaa<br />
aaaaa<br />
<br />
aaaaa<br />
aaaaa<br />
<br />
aaaaa<br />
</div>
</div>
</body>
</html>
Mikel.