/**
  * main action
  */
 public function mainAction()
 {
     require_once 'models/ecommerce/ecommerce_product_to_product.php';
     require_once 'models/ecommerce/ecommerce_product.php';
     $PtP = new ecommerce_product_to_product();
     $Product = new ecommerce_product();
     $product_id = $this->GET['id'];
     $ptp_data = array();
     $ptp_data['product_id'] = $product_id;
     /**
      * saving
      */
     if (is_array($_POST['product_related'])) {
         $current = $PtP->listing("product_id = {$product_id}");
         foreach ($current as $c) {
             $PtP->delete($c['id']);
         }
         foreach ($_POST['product_related'] as $to_id) {
             if (is_numeric($to_id)) {
                 $ptp_data['related_product_id'] = $to_id;
                 $PtP->insert($ptp_data);
             }
         }
     }
     /**
      * listing
      */
     $current = $PtP->listing("product_id = {$product_id}");
     foreach ($current as $c) {
         $detail = $Product->detail($c['related_product_id']);
         if ($detail['publish'] == 0) {
             $detail['class'] = "class='disabled'";
         }
         $this->tpl->assign("CURRENT", $detail);
         $this->tpl->parse("content.ptn");
     }
     return true;
 }