I can′t see my widget

Hi there,
I just created a widget for my child theme this way in my functions.php

<?php
function init_widget_nube() {
	register_sidebar( array(
		'name' => 'Widget Nube',
		'id' => 'widget_nube'
	) );
}
add_action( 'widgets_init', 'init_widget_nube' );
?>

Now I have the region for the widget in my wp-admin, that′s ok, but if I try to move one widget there, nothing appears on my site. Also, I tried with:<?php the_widget('widget_nube'); ?> in my page.php in the place where I want to show the widget but again, nothing on the screen… Can anyone tell me what is happening? I don′t understand what′s going on…

Thanks in advance.