Rule of Service

I want to change the iframe size form terms.php,but it isn't work.

$text = '<a href="'.JRoute::_('index.php?option=com_content&view=article&id='.$terms_article.'&tmpl=component').'" class="modal" rel="{handler: \'iframe\', size: {x: 650, y: 680}}" target="_blank">'.$text.'</a>';

please give me help,thanks