function wp_ajax_delete_meta() {
	$id = isset( $_POST['id'] ) ? (int) $_POST['id'] : 0;

	check_ajax_referer( "delete-meta_$id" );
	if ( ! $meta = get_metadata_by_mid( 'post', $id ) ) {
		wp_die( 1 );
	}

	if ( is_protected_meta( $meta->meta_key, 'post' ) || ! current_user_can( 'delete_post_meta', $meta->post_id, $meta->meta_key ) ) {
		wp_die( -1 );
	}
	if ( delete_meta( $meta->meta_id ) ) {
		wp_die( 1 );
	}
	wp_die( 0 );
}