I don't want Courier drop down on ORDER PAGE, because my client will send an email to the buyer about how to pay. So no need for selecting any Courier type in... If I delete drop down script, then it will appear an error page it said I HAVE TO FILL IN ALL SECTION OF FORM.
try to change courier field as hidden with some default value (some created courier id - such as "delivery" or something) then you don't need to turn it off in lot of places...