Widgets do not work

I created a widget area but every widget I drag to that area does not work, I save the settings and the widget goes to the inactive widgets area. Here is my function.php file with area creation:

function widget()
{
    register_sidebar (array(
    'name' => 'Sidebar Comentadores',
    'id' => 'Comentadores',
    'before_widget' => '<ul>',
    'after_widget' => '</ul>',
    'before_title' => '<h1>',
    'after_title' => '</h1>',
    ));
}
add_action('widgets_init', 'widget');