Due to the complex nature of implanting custom checkouts, all support related to building or troubleshooting a custom checkout is considered premium support which has an hourly cost associated with it.
All questions related to using this API are beyond the scope of regular free email or phone support.
You should factor this in when considering whether to build a custom checkout.

You may find help within the UltraCart forums. Many of the UltraCart merchants have ungodly javascript skills. If you're having trouble, please use the common etiquette for posting your issues.
DO NOT POST:

I'm using the Checkout API and I'm getting a null value.

DO POST:

I'm using the Checkout API.
I'm having a problem with XXX method call.
Here's the URL to the page I'm working on: http://mysite.com/checkout.html.
The problem is happening on line XXX of script XXX.
I've tested it with Chrome, Firefox, IE, and Safari and here are the differences: ... ...
I've attached a screenshot of the error.

Help us help you.

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