Couldn't you just use a switch statement instead. Much more effective than jumping to name tags in a page.
<?
switch($nav)
{
case news:
?>
<!-- all your html for your news section -->
<?
break;
case contact:
?>
<!-- all your html for your contact section -->
?
break;
}
?>
so if you go to the link index.php?nav=news it will show the news section or nav=contact will show the contact section.
Anyway, just an idea
Ant