How to add wysiwyg editor in Wordpress meta box

How to add wysiwyg editor in Wordpress meta box

<?php 
add_action( 'add_meta_boxes', 'adding_new_metaabox' );              
function adding_new_metaabox() 
    {   
        add_meta_box('adsexcerptid', 'Ads Content', 'my_output_function');
    }

function my_output_function( $post ) 
    {
    $settings = array(
        'quicktags'     => array( 'buttons' => 'em,strong,link' ),
        'textarea_name' => 'ads-excerpt',
        'quicktags'     => true,
        'tinymce'       => true
        );
    wp_editor( htmlspecialchars_decode(get_post_meta($_GET['post'], 'ads_excerpt_content' , true )), 'mettaabox_ID_stylee', $settings );
    }


function save_my_postdata( $post_id ) 
{                   
    if (!empty($_POST['ads-excerpt']))
        {
        update_post_meta($post_id, 'ads_excerpt_content', htmlspecialchars($_POST['ads-excerpt']) );
        }
}
add_action( 'save_post', 'save_my_postdata' );