Most order forms use a dialog when creating a new record. This is because the fields that are needed for order creation are not the same as those displayed on the header section of the form. The dialog can be designed specifically to bring all the fields the user will want, all in view without having to hunt the various fast tabs for the field.
The complexity in the process is the interplay between the order form's data source and the dialog used to create the record. The pattern is the same for 'create forms'.
