public function addExportToBulkAction($observer)
    {
        if (! $observer->block instanceof Mage_Adminhtml_Block_Sales_Order_Grid) {
            return;
        }

        $observer->block->getMassactionBlock()->addItem('eparcelexport', array(
            'label' => $observer->block->__('Export to CSV (eParcel)'),
            'url' => $observer->block->getUrl('*/australia_eparcel/export')
        ));
    }