custom gallery

// Post Thumbnails
add_theme_support( 'post-thumbnails' );
set_post_thumbnail_size( 210, 102, true );
add_image_size( 'gallery-size', 680, 380, true );

// Custom Gallery shortcode
    add_shortcode('gallery_home', 'homepg_gallery_shortcode');

    function homepg_gallery_shortcode($attr) {
        global $post;

        static $instance = 0;
        $instance++;

        // We're trusting author input, so let's at least make sure it looks like a valid orderby statement
        if ( isset( $attr['orderby'] ) ) {
            $attr['orderby'] = sanitize_sql_orderby( $attr['orderby'] );
        if ( !$attr['orderby'] )
            unset( $attr['orderby'] );
        }

        extract(shortcode_atts(array(
            'order' => 'ASC',
            'orderby' => 'menu_order ID',
            'id' => $post->ID,
            'itemtag' => 'dl',
            'icontag' => 'dt',
            'captiontag' => 'dd',
            'columns' => 3,
            'size' => 'gallery-size',
            'include' => '',
            'exclude' => ''
        ), $attr));

        $id = intval($id);
        if ( 'RAND' == $order )
        $orderby = 'none';

        if ( !empty($include) ) {
            $include = preg_replace( '/[^0-9,]+/', '', $include );
            $_attachments = get_posts( array('include' => $include, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );

            $attachments = array();
            foreach ( $_attachments as $key => $val ) {
                $attachments[$val->ID] = $_attachments[$key];
            }
        } elseif ( !empty($exclude) ) {
            $exclude = preg_replace( '/[^0-9,]+/', '', $exclude );
            $attachments = get_children( array('post_parent' => $id, 'exclude' => $exclude, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );
        } else {
            $attachments = get_children( array('post_parent' => $id, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );
        }

        if ( empty($attachments) )
            return '';

        if ( is_feed() ) {
            $output = "";
            foreach ( $attachments as $att_id => $attachment )
            $output .= wp_get_attachment_link($att_id, $size, true) . "";
            return $output;
        }

        // check to see if tags have been set to false. If they are the defaults or have been set to a string value use that as the tag.
        if ($itemtag) $itemtag = tag_escape($itemtag);
        if ($captiontag) $captiontag = tag_escape($captiontag);
        if ($icontag) $icontag = tag_escape($icontag);
        $columns = intval($columns);

        $selector = "gallery-{$instance}";

        $output = "";

        $i = 0;
        foreach ( $attachments as $id => $attachment ) {
        ++$i;
        $link = isset($attr['link']) && 'file' == $attr['link'] ? wp_get_attachment_image($id, $size, false) : wp_get_attachment_image($id, $size, false);

        if ($itemtag) {
            $output .= '';
        if( $columns > 0 && $i % $columns == 0 ) $output .= "";
            $output .= '';
        }
        if ($icontag) $output .= "";
            $output .= "".$link;
        if ($icontag) $output .= "";

        // if the attachment has a caption set
        if ( trim($attachment->post_excerpt) ) {
            if ($captiontag) $output .= "";
                $output .= wptexturize($attachment->post_excerpt);
            if ($captiontag) $output .= "";
        }
        if ($itemtag) $output .= "";
            if ( $columns > 0 && $i % $columns == 0 ) $output .= "";
        }

        $output .= "";

        return $output;
    }