I would recommend using the WP_Nav Menu for your site. To use this feature, just add this in place of your current nav:
<?php
add_action( 'init', 'register_my_menus' );
function register_my_menus() {
register_nav_menus(
array(
'primary-menu' => __( 'Main Menu' ),
'secondary-menu' => __( 'Secondary Menu' ),
'tertiary-menu' => __( 'Tertiary Menu' )
)
);
}
?>
Then you can use this to display the navigation in your template files:
<div id="menu">
<?php wp_nav_menu( array( 'theme_location' => 'primary-menu' ) ); ?><!-- End Navigation -->
</div><!-- End #menu-->
With the code above you can use up to 3 menu’s in different locations. To add another, just change the ‘primary-menu’ in the example above to one of the other 3 listed in the functions.php file. You can now go to the WP-Admin>Appearance>Menu’s and create your nav menu and add the pages/posts, or categories/tags to the menu and make it as many levels deep as you wish.