custom tag: using el inside el

hi all,

iam trying to make a facelets tag which should render a link which style should be depending on a request param. to avoid copy paste code it whould be nice to handle this via a facelets tag. Here is what i want to do in a tag named categoryItem:

<ui:composition>
        <h:outputLink styleClass="#{param['id']==${itemid}?'selected':'unselected'}">
                <f:param name="id" value="${itemid}" />
                <h:outputText value="${itemvalue}" />
        </h:outputLink>
</ui:composition>

the call whould be something like this:
<a:categoryItem itemid="3" itemvalue="LinkValue1"/>

if i run this it says:
javax.servlet.ServletException: Error Parsing: #{param['id']==${itemid}?'selected':'unselected'}

I dont wonder about this error message but does anyone know if it is possible to do something like this?

thanks for guesses