Fatal error: Call to undefined function register_column_headers() in C:\wamp\www\wordpress2\wp-content\plugins\pro-questions\admin-list-site.php on line 7

<?php
/*
Plugin Name: Plugin Tutorial
Plugin URI: http://www.pro-questions.com
Description: Wordpress plugin tutorial
Author: Pro Question
Version: 1.0.1
Author URI: http://pro-questions.com
*/

$siteurl = get_option('siteurl');
define('PRO_FOLDER', dirname(plugin_basename(__FILE__)));
define('PRO_URL', $siteurl.'/wp-content/plugins/' . PRO_FOLDER);
define('PRO_FILE_PATH', dirname(__FILE__));
define('PRO_DIR_NAME', basename(PRO_FILE_PATH));
// this is the table prefix
global $wpdb;
$pro_table_prefix=$wpdb->prefix.'pro_';
define('PRO_TABLE_PREFIX', $pro_table_prefix);

register_activation_hook(__FILE__,'pro_install');
register_deactivation_hook(__FILE__ , 'pro_uninstall' );

function pro_install()
{
global $wpdb;
$table = PRO_TABLE_PREFIX."tutorial";
$structure = "CREATE TABLE $table (
id INT(9) NOT NULL AUTO_INCREMENT,
name VARCHAR(80) NOT NULL,
website VARCHAR(20) NOT NULL,
description text,
UNIQUE KEY id (id)
);";
$wpdb->query($structure);
// Populate table
$wpdb->query("INSERT INTO $table(name, website, description)
VALUES('Pro Questions', 'pro-questions.com','This Is A Programming Questions Site')");
}

function pro_uninstall()
{
global $wpdb;
$table = PRO_TABLE_PREFIX."tutorial";
$structure = "drop table if exists $table";
$wpdb->query($structure);
}

add_action('admin_menu','pro_admin_menu');

function pro_admin_menu() {
add_menu_page(
"Plugin tutorial",
"Plugin tutorial",
8,
__FILE__,
"pro_admin_menu_list",
PRO_URL."/images/menu.gif"
);
add_submenu_page(__FILE__,'Site list','Site list','8','list-site','pro_admin_list_site');
}

function pro_admin_menu_list()
{
echo "Now i know how to create a plugin in wordpress!";
}
// function for the site listing
function pro_admin_list_site()
{
include 'admin-list-site.php';
}

//Add ShortCode for "front end listing"
add_shortcode("pro_tutorial_site_listing","pro_tutorial_site_listing_shortcode");
function pro_tutorial_site_listing_shortcode($atts)
{
include 'admin-list-site.php';
}

<?php
$columns = array(
'name' => 'Name',
'website' => 'Website',
'description' => 'Description'
);
register_column_headers('pro-list-site', $columns);
?>
<div class="wrap">
<?php echo "<h2>" . __( 'Site Listing' ) . "</h2>"; ?>
<table class="widefat page fixed" cellspacing="0">
<thead>
<tr>
<?php print_column_headers('pro-list-site'); ?>
</tr>
</thead>

<tfoot>
<tr>
<?php print_column_headers('pro-list-site', false); ?>
</tr>
</tfoot>
<tbody>
<?php
global $wpdb;
$sql = "SELECT *FROM ".PRO_TABLE_PREFIX."tutorial where 1";
$results = $wpdb->get_results($sql);
if(count($results) > 0)
{
foreach($results as $result)
{
echo "<tr>
<td>".$result-> name."</td><td>".$result->website."</td><td>".$result->description."</td>
</tr>";
}
}
?>
</tbody>
</table>
</div>