I'm using version 1.1, with a custom JSON cart instead of the cart template hosted on our foxycart domain. So a user will go to this custom cart page and any changes made are done through JSON. The reason for this is we wanted to allow customers to "round up" their order (we're an NGO, so purchases are actually donations). Anyway, the issue I am having now is with implementation of coupon codes. Adding them is fine, but is there a way that a coupon code can be removed and the cart updated through JSON?