Check if page is parent, child in wordpress

Check if page is parent, child in wordpress

function is_tree($pid) {      
  // $pid = The ID of the page we're looking for pages underneath
	global $post;        
	// load details about this page
	if(is_page()&&($post->post_parent==$pid||is_page($pid)))
    return true;   // we're at the page or at a sub page
	else
    return false;  // we're elsewhere
};