//this is my index file on totaljokes-error( a folder name)

<?php
include_once $_SERVER['DOCUMENT_ROOT'] . '/includes/db.inc.php';

function totaljokes()
{
try
{
$result=$pdo->query('SELECT COUNT(*) FROM joke');
}
catch (PDOException $e)
{
$error='Database error counting jokes!';
include 'error.html.php';
exit();
}

$row=$result->fetch();
return $row[0];
}


//Even my folder "includes" contained file "error.html.php" and "db.inc.php" in directory wamp/www, but the http://localhost/totaljokes-error/ showed nothing, just blank. Am i wrong placed my file or what else? I'm blur with the share include file in directory.

Any help is appreciated.