title: Joomla 2.5 Virtuemart hook method in a custom plugin wont fire
body: <p>I managed to create this simple plugin that I need it to fire a method when ever an item is added to the cart and a method to fire when a checkout has happend. But those methods wont fire in anyway. I also seen another plugin named stockable in virtuemart that uses plgVmOnAddToCart and it fires there correctly. But in my plugins class it wont fire at all. 
  Here is my code in my plugin, what can I do to make it work? thank you</p>
  
  <pre><code>&lt;?php
  defined('_JEXEC') or    die( 'Direct Access to ' . basename( __FILE__ ) . ' is not allowed.' ) ;
  
  if (!class_exists('vmCustomPlugin')) require(JPATH_VM_PLUGINS . DS . 'vmcustomplugin.php');
  
  class plgVmAftercheckout extends vmCustomPlugin {
      private $stockhandle = 0;
  
      function __construct(&amp; $subject, $config) {
          parent::__construct($subject, $config);
  
          $varsToPush = array(
              'selectname1'=&gt;array('','char'),'selectname2'=&gt;array('','char'),'selectname3'=&gt;array('','char'),'selectname4'=&gt;array('','char'),
              'selectoptions1'=&gt;array('','char'),'selectoptions2'=&gt;array('','char'),'selectoptions3'=&gt;array('','char'),'selectoptions4'=&gt;array('','char')
          );
  
          $this-&gt;setConfigParameterable('custom_params',$varsToPush);
  
      }
  
      public function plgVmOnAddToCart(&amp;$product){
  
          echo "plgVmOnAddToCart fired";
          die();
      } 
      public function plgVmOnUserInvoice(){
          echo "plgVmOnUserInvoice fired";
          die();
      }
  
  
  }
  
  ?&gt;
  </code></pre>