Add class instead of hard coded width

The modal popup for notice.php has a hard coded width which is found here:

administrator/components/com_hikashop/helpers/cart.php

And looks like this:

echo '<div style="display:none;">'.
'<a rel="{handler: \'iframe\',size: {x: 675, y: 450}}" id="hikashop_notice_box_trigger_link" ref="'.hikashop_completeLink('checkout&task=notice'.$url_itemid,true).'"> </a>'.

This is not optimal for responsive design and mobile templates. How can we set a class instead for the width?

Thanks

The popup system of joomla 1.5 and 2.5 is not meant to be responsive.
You can't add a class as the size parameters you see there are not for the CSS by for the javascript to determine the size of the popup.
For Joomla 3.0, they plan on changing the popup system and maybe will allow the size to be dynamic.

Thanks