Problem loading the .js files

[devwal]

I tried using the example code and noticed it doesn't load the required .js files.
Only after adding it myself it worked:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/amcharts.js"></script>
<?php

include_once '/vendor/autoload.php';
use AmCharts\Chart,
    AmCharts\Manager as ChartManager;


$manager = ChartManager::getInstance();
$manager->setAmChartsPath('./amcharts.js');


$pie = new Chart\Pie();
$pie->setDataProvider(array(
    array(
        'name' => 'Foo',
        'value' => 1
    ),
    array(
        'name' => 'Bar',
        'value' => 3
    ),
    array(
        'name' => 'Baz',
        'value' => 2
    )
));
$pie->setTitleField('name')
    ->setValueField('value');

echo $pie->render();

?>