Though its an old thread, thought this might help someone new to this:
I have used the plugin http://www.curvycorners.net
I was trying to apply the corners to the rich panel id directly (myBox), but after a while i found that the generated div's ids are not exactly the same (myBoxContentDiv, myBoxShadowDiv).
<script type="text/JavaScript" src="js/curvycorners.js"></script>
<script type="text/JavaScript">
function round() {
var settings = {
tl: {
radius: 20
},
tr: {
radius: 20
},
bl: {
radius: 20
},
br: {
radius: 20
},
antiAlias: true
};
//to round the modal panel
curvyCorners(settings, '#myBoxContentDiv');
//to round the shadow around the modal panel
curvyCorners(settings, '#myBoxShadowDiv');
}
</script>
<body>
<rich:modalPanel id="myBox" onshow="round()" width="350" height="100">
<h:outputText value="Demo - rounded edge modal panel"></h:outputText>
</rich:modalPanel>
<h:form>
<h:outputLink value="#" id="link">
Show Modal Panel
<rich:componentControl for="myBox" attachTo="link" operation="show" event="onclick"/>
</h:outputLink>
</h:form>
</body>