Including gallery2embedded.php in a php site.

I am trying to integrate gallery2 to into a php site. I made a file called gallery2embedded.php which is explained here: http://codex.gallery2.org/Gallery2:How_to_visually_embed_G2_in_your_own_website_using_embedded_mode

The script itself works perfect!
I had problems setting it up in a subfolder and not directly in the "gallery2" folder. I changed the paths but I must have missed something!

$g2_Config['path'] = dirname(__FILE__) . '/../';
$g2_Config['g2Uri'] = '../gallery2/';
$g2_Config['embedUri'] = '../gallery2/subfolder/gallery2embedded.php';

The pictures are missing and it looks like the css is missing.

So I decided to try if I could include the gallery2embedded.php file in another php site directly from the gallery2 folder. So I uploaded a php file into the gallery2 folder and included the gallery2embedded.php file. The problem here is that the pictures are not displayed and it seems like the css is missing. When I navigate directly to the gallery2embedded.php file everything is displayed the way it should.

I would appreciate some help, because I already searched the forum and didn't find anything that helped me with those problems.