UltraCart's single page and multi-page checkout work perfectly for the average merchant, but some merchants would like to have more flexibility in the way their shopping cart is displayed. Using the JavaScript API Checkout allows you to design the page in any fashion and still use the advanced logic and options of the full UltraCart checkout. Some examples of functionality that you can utilize with the JS API Checkout are: instant information transfer (capture valuable customer information even if they abandon), your custom design and functionality, checkout can be on any server, error messages rendered on page, custom questions and forms, tailored to your business = higher conversion!!!