Drupal: node_load() in php file - load via ajax i try to load a node in Drupal 7 in a php file, which will be loaded with ajax.

my php file looks like this:

require_once '../../../includes/bootstrap.inc';
$i = 16;
$content = node_load($i);


The include of bootstrap.inc works fine, but this file returns 'PHP Fatal error: Call to undefined function node_load()'. i guess i've read that the function node_load needs the bootstrap.inc file, but it doesnt seems so. 

Is there any possible way to use the node_load function right without 'register' a module in drupal - i just want to load a self made php file, which just returns the content of a node - without the template!
Rather than using a custom php file you should attempt to solve the issue "the drupal way" via a custom module or in your template.php... Please see my answer in this question.

It explains how you can add to the original url to change the template (or create a blank template so it is only node data presetned).