How to pass dynamic values to by EL?

[Song Chao]

Hi, all
I found that it doesn't work when I pass values by EL to <portlet param >,
such as

<portlet:actionURL var="action_add_url">
   <portlet:param name="id" value="${item.id}" />
</portlet:actionURL>


How to solve this problem? Please show me some examples.

Thanks.

Bob Song