Hi John,
The syntax has not changed. If you want to set some attributes unconditionally based on values of some other attributes, you can do it like this:
If Invoice.PaymentType = "Paid By Cheque"
Then Invoice.BankAccountNo = Invoice.Customer.BankAccountNo
If you do not want to overwrite the previous value if there was one from the previous selection or user input, you need to add a condition to check if the value is empty:
If Invoice.PaymentType = "Paid By Cheque" AND Invoice.BankAccountNo IS UNDEFINED
Then Invoice.BankAccountNo = Invoice.Customer.BankAccountNo