[WP] - Add youtube thumbnail posts with custom metabox

gistfile1.aw

// http://wpsnipp.com/index.php/functions-php/add-youtube-thumbnail-posts-with-custom-metabox/

        add_action("admin_init", "youtube_init");
        add_action('save_post', 'save_youtube_link');
        function youtube_init(){
                add_meta_box("youtube", "Youtube thumbnail code", "youtube_link", "post", "normal", "high");
        }
        function youtube_link(){
                global $post;
                $custom  = get_post_custom($post->ID);
                $link    = $custom["link"][0];
?>
<div class="link_header">
        <input name="link" class="form-input-tip" value="<?php echo $link; ?>" /><br />
</div>
<div class="yt-thumb"><img src="http://img.youtube.com/vi/<? echo $custom['link'][0]; ?>/0.jpg" width="30" height="30" /></div>
<p>Please place id for the youtube file here! This sample URL ID is hilighted in <span class="yt-id">red</span>. After v= and before & symbol if one exists. <br /> http://www.youtube.com/watch?v=<span class="yt-id">oHg5SJYRHA0</span>&feature=player_embedded</p><div class="yt-clear"></div>
<?php
        }
function save_youtube_link(){
global $post;
if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) {return $post->ID;}
        update_post_meta($post->ID, "link", $_POST["link"]);
}
function youtube_thumb($w,$h,$t){
     $custom = get_post_custom($post->ID);
     return '<img src="http://img.youtube.com/vi/'.$custom['link'][0].'/'.$t.'.jpg" width="'.$w.'" height="'.$h.'" />';
}
add_action('admin_head', 'youtube_css');
function youtube_css() {
        echo'
        <style type="text/css">
                .link_header{margin:0px 5px 0px 0px;}
                .link_header input{
                        font-size:13px;
                        color:#666;
                        border:solid 1px #ccc;
                        -moz-border-radius:3px;
                        padding:2px;
                        margin:0px 10px 0px 0px;
                        width:100%;
                        }
                .yt-clear{clear:both;}
                .yt-id{color:#ff0000;font-weight:bold;}
                .yt-thumb{
                        float:left;
                        margin:6px 6px 0px 0px;
                        border:solid 1px #ccc;
                        }
        </style>
        ';
}