dynamic sidebar

Hi

Can anyone offer some help with a problem I am having.

I have a sub navigation in my sidebar which i want to to be highlighted when on that page (of course).

U can see it here: http://paradoxbangkok.com

the sub nav:

GASTRONOMY
EVENTS
PROMOTIONS

when on one of these pages I want the background to be highlighted. I am familiar with dynamic menu highlighting

<li<?php
if (is_page('gastronomy'))
{
echo " id=\"current\">";
?>
<a>/gastronomy">GASTRONOMY &raquo;</a>
<?php
}
?>

But that only works when I am on one of the sub nav pages. If I am on any other page the menu disappears. I suspect its something like an elseif statment. Basically, always show the subnav, but if on one of the pages in the subnav highlight it.

What am I missing? any thoughts would be great

Thanks

Rob