Get parent page ID if exists

This is a great little snippet that will let you return the ID of the parent page if the page has a parent.

Code Snippet:

<?php

function is_subpage() {
    global $post;
    if ( is_page() && $post->post_parent ) {
        return $post->post_parent;
    } else {
        return false;
    }
}

?>

Posted in Pages, Conditional