add to cart button

-- url of the page with the problem -- : sharpylook.com
-- HikaShop version -- : 2.3.0
-- Joomla version -- : 3.2.3
-- PHP version -- : 5.3
-- Browser(s) name and version -- : Internet Explorer 11
-- Error-message(debug-mod must be tuned on) -- : Error_message

The "add to cart button" doesn't work, it isn't clickable, could you guys please help. It works with Firefox but, not with Internet Explorer.