WordPress Sidebar Menu for Pages

wp-sidebar-menu.php

<?php
  	
	/* check whether the current post has a parent */
	if( $post->post_parent )	{
		
		/* get the ancestors/parent of the current post */
		$pxjn_ancestors = get_post_ancestors( $post->ID );
		
		/* count the number of parents retrieved less 1 */
		$pxjn_root = count( $pxjn_ancestors ) -1;
		
		/* set the parent to the */
		$pxjn_parent = $pxjn_ancestors[ $pxjn_root ];
	
	/* current post has no parent */
	} else {
		
		/* set current post id as post parent */
		$pxjn_parent = $post->ID;
		
	} // end if current post has parent
	
	/* set the title variable to the post parent page */
	$pxjn_title = wp_list_pages( 'title_li=&echo=0&include='.$pxjn_parent );
	
	/* get the children of the current post */
	$pxjn_children = wp_list_pages( 'title_li=&child_of='. $pxjn_parent .'&echo=0&depth=1&orderby=menu_order&order=ASC' );
	
	/* if any children are returned/present */
	if ($pxjn_children) {
		
		/* output some html to wrap our menu in */
		echo '<nav class="subnav"><ul id="nav" class="subnav-menu">';
			
			/* output the parent page title and the child pages as list items */
			echo $pxjn_title; echo $pxjn_children;
		
		/* close our html tags for the list */
		echo '</ul></nav>';
				    
	} // end if page has children

?>