This is just a quick one that a few people seem to trip up on because it seems to be such a simple thing to do. If you store a List, lets call it people, in say the session scope you might expect to be able to display it's size like this:

<h:outputText value="#{people.size}"/>

However that won't work because the List.size() method is not a bean pattern. There is a fix for this in the JSTL but as far as I know there is no way to access this property using JSF. If the List is wrapped in another class one option is to put get and set methods on that class. Not a nice solution but it should work. An alternative solution is to use the new length function from JSTL1.1 like this:

<c:out value="${fn:length(advanced_search.clientPackages)}"/>