$saved = number_format_i18n($packs * $price, 2);

function is_sidebar_active($index) {
	global $wp_registered_sidebars;
 
	$widgetcolums = wp_get_sidebars_widgets();
 
	if ($widgetcolums[$index])
		return true;
 
	return false;
}

<?php if ( function_exists('is_sidebar_active') && is_sidebar_active('sidebar') ) { ?>
	<div id="sidebar">
		<ul>
			<?php dynamic_sidebar('sidebar'); ?>
		</ul>
	</div>
<?php } ?>

<?php
class wpe_comment_widget extends WP_Widget {
 
    function wpe_comment_widget() {
        $widget_ops = array('classname' => 'wpe_widget_comments', 'description' => __( 'Your comments and commentform', 'your_textdomain') );
        $this->WP_Widget('wpe-comment-widget', __('WPE Comments', 'your_textdomain'), $widget_ops);
    }
 
    function widget($args, $instance) {
        if(is_single()) {
            extract($args);
            global $post;
            echo $before_widget;
            comments_template();
            echo $after_widget;
        }
    }
 
    function update($new_instance, $old_instance) {
        $instance = $old_instance;
        return $instance;
    }
 
    function form($instance) {
        ?>
        <p><?php _e('This widget will only be displayed in single view.', 'your_textdomain'); ?></p>
       <?php
    }
}
 
register_widget('wpe_comment_widget');
?>

// unregister all default WP Widgets
function unregister_default_wp_widgets() {
 
	unregister_widget('WP_Widget_Pages');
 
	unregister_widget('WP_Widget_Calendar');
 
	unregister_widget('WP_Widget_Archives');
 
	unregister_widget('WP_Widget_Links');
 
	unregister_widget('WP_Widget_Meta');
 
	unregister_widget('WP_Widget_Search');
 
	unregister_widget('WP_Widget_Text');
 
	unregister_widget('WP_Widget_Categories');
 
	unregister_widget('WP_Widget_Recent_Posts');
 
	unregister_widget('WP_Widget_Recent_Comments');
 
	unregister_widget('WP_Widget_RSS');
 
	unregister_widget('WP_Widget_Tag_Cloud');
}
 
add_action('widgets_init', 'unregister_default_wp_widgets', 1);

<?php
if (class_exists('WP_Widget')) {
    class WPE_Widget_Post_Navigation extends WP_Widget {
 
        function WPE_Widget_Post_Navigation() {
            $widget_ops = array('classname' => 'wpe_widget_post_navi', 'description' => __( "Some posts before and after the current post") );
            $this->WP_Widget('wpe-post-navi', __('WPE Single Post Navigation'), $widget_ops);
        }
 
        function widget($args, $instance) {
            if(is_single()) {
                global $post, $wpdb;
                extract($args);
 
                if ( !$number = (int) $instance['number'] )
                    $number = 5;
                elseif( $number < 1 )
                    $number = 1;
                elseif( $number > 10 )
                    $number = 10;
 
                $title_before 		= apply_filters('widget_title', empty($instance['title_before']) ? 'Posts before' : $instance['title_before']);
                $title_after	 	= apply_filters('widget_title', empty($instance['title_after']) ? 'Posts after' : $instance['title_after']);
                $before_widget_2	= preg_replace("/(wpe\-post\-navi-\d+)/", "$1-1", $before_widget);
 
                $querystr = "
                    SELECT *
                    FROM $wpdb->posts wposts
                    WHERE wposts.ID != $post->ID
                    AND wposts.post_type = 'post'
                    AND wposts.post_status = 'publish'
                    AND wposts.post_date %s '$post->post_date'
                    ORDER BY wposts.post_date %s
                    LIMIT $number
                 ";
 
                $leading_posts = $wpdb->get_results(sprintf($querystr, '<', 'DESC'), OBJECT);
                $trailing_posts = $wpdb->get_results(sprintf($querystr, '>', 'ASC'), OBJECT);
 
                if ($trailing_posts && count($trailing_posts)) {
                    echo $before_widget_2 . $before_title . $title_before . $after_title . "<ul>";
                    $trailing_posts = array_reverse($trailing_posts);
                    foreach ($trailing_posts as $post) {
                        setup_postdata($post);
                        ?> <li><a href="<?php the_permalink() ?>" title="<?php echo esc_attr(get_the_title() ? get_the_title() : get_the_ID()); ?>"><?php if ( get_the_title() ) the_title(); else the_ID(); ?> </a></li><?php
                    }
                    echo "</ul>" . $after_widget;
                }
 
                if ($leading_posts && count($leading_posts)) {
                    echo $before_widget . $before_title . $title_after . $after_title . "<ul>";
                    foreach ($leading_posts as $post) {
                        setup_postdata($post);
                        ?> <li><a href="<?php the_permalink() ?>" title="<?php echo esc_attr(get_the_title() ? get_the_title() : get_the_ID()); ?>"><?php if ( get_the_title() ) the_title(); else the_ID(); ?> </a></li><?php
                    }
                    echo "</ul>" . $after_widget;
                }
                wp_reset_query();
            }
        }
 
        function update( $new_instance, $old_instance ) {
            $instance = $old_instance;
            $instance['title_before'] = strip_tags($new_instance['title_before']);
            $instance['number'] = (int) $new_instance['number'];
            $instance['title_after'] = strip_tags($new_instance['title_after']);
 
            return $instance;
        }
        function form( $instance ) {
            $title_before = ($instance['title_before'] == '') ? 'Posts before' : esc_attr($instance['title_before']);
            $title_after = ($instance['title_after'] == '') ? 'Posts after' : esc_attr($instance['title_after']);
            if ( !$number = (int) $instance['number'] )
                $number = 5;
            elseif ( $number < 1 )
                $number = 1;
            elseif ( $number > 10 )
                $number = 10;
    ?>
            <p><label for="<?php echo $this->get_field_id('title_before'); ?>">Title before:</label>
            <input class="widefat" id="<?php echo $this->get_field_id('title_before'); ?>" name="<?php echo $this->get_field_name('title_before'); ?>" type="text" value="<?php echo $title_before; ?>" /></p>
            <p><label for="<?php echo $this->get_field_id('title_after'); ?>">Title after:</label>
            <input class="widefat" id="<?php echo $this->get_field_id('title_after'); ?>" name="<?php echo $this->get_field_name('title_after'); ?>" type="text" value="<?php echo $title_after; ?>" /></p>
            <p><label for="<?php echo $this->get_field_id('number'); ?>">Number of posts to show before and after current post:</label>
            <input id="<?php echo $this->get_field_id('number'); ?>" name="<?php echo $this->get_field_name('number'); ?>" type="text" value="<?php echo $number; ?>" size="3" /><br />
            <small>(at most 10)</small></p>
    <?php
        }
    }
    register_widget('WPE_Widget_Post_Navigation');
}
?>

$before_widget_2 = preg_replace("/(wpe\-post\-navi-\d+)/", "$1-1", $before_widget);

class My_RSS_Widget extends WP_Widget {
	function My_RSS_Widget() {
		//Constructor
	}
 
	function widget($args, $instance) {
		// prints the widget
	}
 
	function update($new_instance, $old_instance) {
		//save the widget
	}
 
	function form($instance) {
		//widgetform in backend
	}
}
register_widget('My_RSS_Widget');

class My_RSS_Widget extends WP_Widget {
	function My_RSS_Widget() {
		$widget_ops = array('classname' => 'widget_rss_links', 'description' => 'A list with your feeds links' );
		$this->WP_Widget('rss_links', 'Feed links', $widget_ops);
	}
 
	function widget($args, $instance) {
		extract($args, EXTR_SKIP);
 
		echo $before_widget;
		$title = empty($instance['title']) ? ' ' : apply_filters('widget_title', $instance['title']);
		$entry_title = empty($instance['entry_title']) ? ' ' : apply_filters('widget_entry_title', $instance['entry_title']);
		$comments_title = empty($instance['comments_title']) ? ' ' : apply_filters('widget_comments_title', $instance['comments_title']);
 
		if ( !empty( $title ) ) { echo $before_title . $title . $after_title; };
		echo '<ul id="rss">';
		echo '  <li><a href=" ' . get_bloginfo('rss2_url') . '" rel="nofollow" title=" ' . $entry_title . ' ">' . $entry_title . '</a></li>';
		echo '  <li><a href=" ' . get_bloginfo('comments_rss2_url') . '" rel="nofollow" title="  '. $comments_title . ' ">' . $comments_title . '</a></li>';
		echo '</ul>';
		echo $after_widget;
	}
 
	function update($new_instance, $old_instance) {
		$instance = $old_instance;
		$instance['title'] = strip_tags($new_instance['title']);
		$instance['entry_title'] = strip_tags($new_instance['entry_title']);
		$instance['comments_title'] = strip_tags($new_instance['comments_title']);
 
		return $instance;
	}
 
	function form($instance) {
		$instance = wp_parse_args( (array) $instance, array( 'title' => '', 'entry_title' => '', 'comments_title' => '' ) );
		$title = strip_tags($instance['title']);
		$entry_title = strip_tags($instance['entry_title']);
		$comments_title = strip_tags($instance['comments_title']);
?>
			<p><label for="<?php echo $this->get_field_id('title'); ?>">Title: <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo attribute_escape($title); ?>" /></label></p>
			<p><label for="<?php echo $this->get_field_id('entry_title'); ?>">Title for entry feed: <input class="widefat" id="<?php echo $this->get_field_id('entry_title'); ?>" name="<?php echo $this->get_field_name('entry_title'); ?>" type="text" value="<?php echo attribute_escape($entry_title); ?>" /></label></p>
			<p><label for="<?php echo $this->get_field_id('comments_title'); ?>">Title for comments feed: <input class="widefat" id="<?php echo $this->get_field_id('comments_title'); ?>" name="<?php echo $this->get_field_name('comments_title'); ?>" type="text" value="<?php echo attribute_escape($comments_title); ?>" /></label></p>
<?php
	}
}
register_widget('My_RSS_Widget');

if ( function_exists('register_sidebar') )
    register_sidebar(array(
        'before_widget' => '<li id="%1$s" class="widget %2$s">',
        'after_widget' => '</li>',
        'before_title' => '<h2 class="widgettitle">',
        'after_title' => '</h2>',
    ));

<?php
if ( function_exists('register_sidebar') )
register_sidebar(array('name'=>'Home Sidebar',
'before_widget' => '<div class="block">',
'after_widget' => '</div><div class="blockfooter"></div>',
'before_title' => '<h3>',
'after_title' => '</h3>',
));
?>
<?php
if ( function_exists('register_sidebar') )
register_sidebar(array('name'=>'Post Sidebar',
'before_widget' => '<div class="block">',
'after_widget' => '</div><div class="blockfooter"></div>',
'before_title' => '<h3>',
'after_title' => '</h3>',
));
?>
<?php
if ( function_exists('register_sidebar') )
register_sidebar(array('name'=>'Page Sidebar',
'before_widget' => '<div class="block">',
'after_widget' => '</div><div class="blockfooter"></div>',
'before_title' => '<h3>',
'after_title' => '</h3>',
));
?>

<?php
$sidebars = array('Home Sidebar', 'Post Sidebar', 'Page Sidebar');
foreach($sidebars as $name) {
	register_sidebar(array('name'=> $name,
		'before_widget' => '<div class="block">',
		'after_widget' => '</div><div class="blockfooter"></div>',
		'before_title' => '<h3>',
		'after_title' => '</h3>',
	));
}
?>

/**
 * Content of Dashboard-Widget
 */
function my_wp_dashboard_test() {
	echo 'Test Add Dashboard-Widget';
}
 
/**
 * add Dashboard Widget via function wp_add_dashboard_widget()
 */
function my_wp_dashboard_setup() {
	wp_add_dashboard_widget( 'my_wp_dashboard_test', __( 'Test My Dashboard' ), 'my_wp_dashboard_test' );
}
 
/**
 * use hook, to integrate new widget
 */
add_action('wp_dashboard_setup', 'my_wp_dashboard_setup');

function wp_add_dashboard_widget( $widget_id, $widget_name, $callback, $control_callback = null )