function showAddForm($plugin_order_orders_id)
 {
     global $CFG_GLPI, $DB;
     $order = new PluginOrderOrder();
     $reference = new PluginOrderReference();
     if ($order->getFromDB($plugin_order_orders_id) && $order->canUpdateOrder()) {
         if ($order->can($plugin_order_orders_id, 'w')) {
             echo "<form method='post' name='order_detail_form' id='order_detail_form'  action=\"" . Toolbox::getItemTypeFormURL('PluginOrderOrder') . "\">";
             echo "<input type='hidden' name='plugin_order_orders_id' value=\"{$plugin_order_orders_id}\">";
             echo "<div class='center'>";
             echo "<table class='tab_cadre_fixe'>";
             echo "<tr><th colspan='7'>" . __("Add to the order", "order") . "</th></tr>";
             if ($order->fields["suppliers_id"]) {
                 echo "<tr>";
                 echo "<th align='center'>" . __("Type") . "</th>";
                 echo "<th align='center'>" . __("Product reference", "order") . "</th>";
                 echo "<th align='center'>" . __("Quantity", "order") . "</th>";
                 echo "<th align='center'>" . __("Unit price tax free", "order") . "</th>";
                 echo "<th align='center'>" . __("VAT", "order") . "</th>";
                 echo "<th align='center'>" . __("Discount (%)", "order") . "</th>";
                 echo "<th></th>";
                 echo "</tr>";
                 echo "<tr>";
                 echo "<td class='tab_bg_1' align='center'>";
                 $params = array('myname' => 'itemtype', 'orders_id' => $order->fields["id"], 'suppliers_id' => $order->fields['suppliers_id'], 'entity' => $order->fields['entities_id'], 'ajax_page' => $CFG_GLPI["root_doc"] . "/plugins/order/ajax/detailref.php", 'filter' => true, 'class' => __CLASS__, 'span' => 'show_reference');
                 $reference->dropdownAllItems($params);
                 echo "</td>";
                 echo "<td class='tab_bg_1' align='center'><span id='show_reference'>&nbsp;</span></td>";
                 echo "<td class='tab_bg_1' align='center'><span id='show_quantity'>&nbsp;</span></td>";
                 echo "<td class='tab_bg_1' align='center'><span id='show_priceht'>&nbsp;</span></td>";
                 echo "<td class='tab_bg_1' align='center'><span id='show_taxe'>&nbsp;</span></td>";
                 echo "<td class='tab_bg_1' align='center'><span id='show_pricediscounted'>&nbsp;</span></td>";
                 echo "<td class='tab_bg_1' align='center'><span id='show_validate'>&nbsp;</span></td>";
                 echo "</tr>";
             } else {
                 echo "<tr class='tab_bg_1'><td align='center'>" . __("Please select a supplier", "order") . "</td></tr>";
             }
             echo "</table></div>";
             Html::closeForm();
         }
     }
 }