Thank you Jason. I have the correct stock level appearing in the hidden form element, depending on selections made by the user from the variable drop down menus.
In the calculation:
abs([Quantity] > [AvailableQuantity])?[Quantity] = [AvailableQuantity]:"
...should the colon and single quote be at the end? I'm getting a "parse error" with that. I looked at the LEDCart_PHP.php file and tried to copy the theory from the other calculations listed but without success (parse errors).
Can you clarify exactly what that needs to be?