Does anyone know how to call a method within a bean that takes a parameter?

Here's the background info..
Hello, I'm new to JSF and Richfaces. I'm trying to create a page that contains a clickable <rich:panel> component within a <rich:datagrid>. Upon clicking on a particular panel within the datagrid, another part of the page is re-rendered to display more details about the particular object represented in the datagrid. I'm using <a4j:support> to handle the onclick event, which calls a method in a managed bean to update the current object. What I want to do is have this method take a parameter which would update this current object to the one being clicked.

Can anyone help, or know how to do this a better way?

thanks in advance.

-cg