Untitled

<html>
<head>
<style type="text/css" media="screen">
.main {
	background-color: grey;
	height: 385px;
}

.main-main {
	margin-right: 260px;
	background: darkblue;
	color: white;
}

.main-rightmenu {
	float: right;
	width: 260px;
	background: darkgreen;
	color: white;
}
</style>
</head>

<body>

<div class="main">
	<div class="main-main">Lorem ipsum dolor sit</div>
	<div class="main-rightmenu">Menu</div>
</div>

</body>
</html>