If you have several payment gateways installed and want to allow your users to choose which
one to use, or you want to allow your users the choice of paying offline (eg. by bank transfer or by
sending a cheque in the post), you can do so by using a dropdown list or option list on your order
form.
Just create a new dropdown list or option list field, and create an option for each payment method
(using the 'options...' button to enter the field options popup).
The 'value' of each option should be
the name of the payment gateway (use the 'Gateway Name' value from the list of payment
gateways - this is typically a single word in lower case, eg. 'paypal'). For offline payments, use a
value of either '-1' or 'offline' (the latter is probably best as it will appear on confirmation e-mails -
you can change the word 'offline' to something else by editing the language file
/administrator/components/com_netinvoice/language/english/netinvoice_english.php, or
equivalent in your language). The 'description' of each option can be anything you like.
You then need to tell nBill that the value from this field should be used as the payment gateway.
To do that, you set the 'Order Value' setting on the edit field popup
to 'Payment Gateway'.
If you accept offline payments, and you have 'Pending Until Paid' switched on (which is the
default and recommended setting) on your order form, you will have to go into the pending order
list and activate the pending order when you receive the offline payment.