How to access data in php transferred via webwrite?

Hey everyone,

I am using webwrite to parse some data to a php script like so:

data = struct('userId', 'testuser','Password', 1234);    
url = 'http://example.info/php/test.php';

options = weboptions('MediaType', 'application/json');
response = webwrite(url, data, options);

I want to access the data originally stored in the struct in my php script, but don't know how I can refer to the parsed data in the php script (is it similar to using "GET" and "POST" when using URL-encoded data?)

To start with, I'd simply like to display the transferred data with php like so:

$data = json_decode($data,true);
echo '<pre>' . print_r($json, true) . '</pre>';

As mentioned above, my problem is how I can get the now json-encoded struct element sent by Matlab into the php variable "$data".

Thanks in advance!