Wordpress custom gallery

// Remove the shortcode function that is already there
remove_shortcode('gallery');
// Add our new one
add_shortcode('gallery', 'djave_gallery_shortcode');

// Define the new gallery function
function djave_gallery_shortcode($atts) {
  // Define some variables
	global $post;
	$retour;
	// Grab the shortcode atts - the important one here is 'ids'
	// Also, set a default image size
	extract(shortcode_atts(array(
		'id' => $post->ID,
		'ids' => "",
		'image_size' => 'medium',
	), $atts));
	// Turn the ids into an array we can loop over
	$image_ids = explode(",", $ids);
	
	// Loop over the array
	foreach($image_ids as $image_id):
		// Grab each image attachment
		$img = wp_get_attachment_image($image_id, $image_size, false);
		// Add it to the return data
		$retour .= $img;
	endforeach;

	// Return that data!
	return $retour;
}