Using a collection of Beans within an ActionForm

["Webb, Ed" <Ed...@news.xtremeinformation.com>]

I need to display several lists of choice to the user. These lists are
variable in length depending on the user. I use an ActionForm which contain
Lists. I populate these with objects that contain String and boolean
properties (name of option and selected flag). I add this to the request
scope under the mapping.getAttribute() key and everything is displayed fine
in my JSP page. However when it comes time to submit the changes a new
ActionForm is created with empty Lists and unsurprisingly I get the error
message:

exception:
javax.servlet.ServletException: BeanUtils.populate 
...
root cause:
java.lang.IndexOutOfBoundsException: Index: 1, Size: 0 
...

Here's a snippet from the JSP page to show how I'm displaying the
information:
...
<c:forEach varStatus="status" var="media" items="${emailalertForm.media}">
	<tr>
		<td><fmt:message key="${media.mediaName}" /></td>
		<td><html:checkbox
property="media[${status.index}].selected" /></td>	</tr>
</c:forEach>
...
The question is how can I display lists of choices to the user and get the
changes the user makes to the checkboxes back to my Action? I've read about
nested beans but the only examples I found only had a single bean and not a
collection. Is it possible or is there a better way to go about this?

Thanks for any advice or pointers,

Ed!