if ($isEditing) {
            $button = new XMLElement('button', __('Delete'));
            $button->setAttributeArray(array('name' => 'action[delete]', 'class' => 'button confirm delete', 'title' => __('Delete this data source'), 'type' => 'submit', 'accesskey' => 'd', 'data-message' => __('Are you sure you want to delete this data source?')));
            $div->appendChild($button);
        }