struts-menu question

Hi all - I'm hoping this is a simple question - we use the struts-menu tag
library to do our menuing system.  I've adapted the SimpleMenuDisplayer to
give us our layout of the menu - however, I have a slight issue (rather
than a problem) -

I wish to be able to change the 'class' (style) of a <td> that a menu item
is located in, when that item is selected. This way I can denote to the
user where he is in the program by highlighting the menu option he clicked
on.

I'm not sure if there's an easy way to do it, I looked in the source
code... it sort of escapes me how it could be done.  Has someone here done
something similar with struts-menu?

Thanks.
Martin