* a3 - amount to billed each recurrence * t3 - time period (D=days, W=weeks, M=months, Y=years) * p3 - number of time periods between each recurrence For the example above, the variables would are: $5.00 USD (a3) every 1 (p3) month (t3) For more information about using Subscriptions and Recurring Payments on your website, including adding automatic trial periods for the subscription, see the