php - Simple html dom parser - nothing happens

I'd like to parse a HTML site via HTML dom parser. My simple code is:

<?php
    require_once 'simple_html_dom.php';
    $html = new simple_html_dom();
    $html->load_file('http://google.de/');
    echo $html->find('img',0)->getAttribute('src');    
?>
Copy code

I've got thesimple_html_dom.php file on my server but when I access the PHP file nothing happens. Blank screen! I tried many different codes, I think the problem is not the code. Do I have to install dom-parser on my server or do I have to have a certain version?