Wordpress test for whether current page is parent or child

function is_has_child();

function is_has_child() {
	global $post;
	if ( is_page() && $post->post_parent ) 
		return true;
	$children = get_pages('child_of='.$post->ID);
	if( count( $children ) != 0 ) 
		return true;
	else
		return false;
}