"Add to Cart" button doesn't do anything

I am trying out the CS cart trial version and I am having trouble getting the Add to Cart button to do anything. I have searched quite a bit and see that others have had problems with the cart dropping the contents of the cart when checking out but this is a different problem.



When I click on the add to cart button, nothing happens; it just sits there. I have checked and double checked all of the file permissions and nothing seems to help.



The site is hosted with siteground if that helps.



Can someone shed some light on this? Thanks.



update



If I change the ajax.js permissions to 711 or 733 the add to cart button works but I lose some functionality in the Admin panel.