How to get s:select id and name under struts2 action?

[red phoenix]

I have a jsp,it contains a s:select,like follows:
<s:select name="test" list="#request.testList" listKey="id"
listValue="tname" size="6" cssClass="tbcell"/>

When this jsp submit,it will submit to a struts2 action,I want to know how
to get all id and name of s:select and how to get selected id and name of
s:select ?
How to do it? An example is better.

Thanks!