lo tengo solucionado
Código PHP:
<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript" src="http://github.com/malsup/corner/raw/master/jquery.corner.js?v2.09"></script>
<script type="text/javascript">
$(this).ready(function() {
$(".adornment_int").corner("round 8px").parent().corner("round 10px");
});
</script>
<style>
.adornment_ext { width: 200px; height: 200px; padding: 3px; background-color:#ff0000;}
.adornment_int { width: 100%; height: 100%; background-color:#00ff00; }
.adornment_contingut { padding: 8px; }
</style>
</head>
<body>
<div class="adornment_ext">
<div class="adornment_int">
<div class="adornment_contingut">Div amb Adornment</div>
</div>
</div>
</body>
</html>