Web service module return bad request

[polaije]

Hi,

I try to devlop a very simple module to access my prestashop site in 1.6.

My code is like this :

 require_once('PSWebServiceLibrary.php');
 try
 { 
  $webService = new PrestaShopWebservice('http://mysite/api/', 'XXXXXXXXXXXXXXXXXXXXXXXXXX', false); 
  $xml = $webService->get(array('resource' => 'product_option_values'));
  //$opt['resource']= 'product_option_values';
  //$xml = $webService->get($opt);
 }
 catch (PrestaShopWebserviceException $ex) {
    // Shows a message related to the error
    echo 'Other error: <br />' . $ex->getMessage();
 }

The module return bad request (err. 400)

The web service works with URL : http://mysite.com/api/product_option_values

 

What I am doing wrong ?

Thanks for helping me.

Jean-Marie