Mh, ho sbagliato un pò di misure, ma penso che rende comunque l'idea.
codice:
<html>
<head>
<title></title>
<meta content="">
<style>
body
{
margin: 0;
padding : 0;
border: 0;
}
#menu
{
overflow: auto;
position: fixed;
left: 0;
top : 0;
height: 100%;
width: 25%;
background-color: red;
}
#container
{
margin: 0 0 0 25%;
padding: 0;
background-color: yellow;
}
</style>
</head>
<body>
<div id="menu">
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</div>
<div id="container">
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</div>
</body>
</html>