add_widget_type('helloworld', '$video_title', 'The hello, world widget');

somethink like this

hey alfalive,

yes the code you listed looks good but the problem $video_title return as  empty in start.php.

but if i test the code below in  my view.php of the widget, it works:

echo $video_title = $vars['entity']->videotitle;

you know how could i pass that data in to start.php