create two subform one for mailing address(put all the fields required for mailing address inside this subform) and another for Delivery address(put all the required fields of delivery address inside this subform).
On the click of mailing address radio button:
form1.firstpage.Subform1.presence="visible";
form1.firstpage.Subform2.presence="invisible";
form1.firstpage.Subform2.h="0";
form1.firstpage.Subform2.w="0";
On the click of Delivery address radio button:
form1.firstpage.Subform2.presence="visible";
form1.firstpage.Subform1.presence="invisible";
form1.firstpage.Subform1.h="0";
form1.firstpage.Subform1.w="0";
form1----Form name
firstpage----Parent page(Must be flowed type).
Subform1---Mailing address subform(Must be flowed type).
Subform1---Mailing address subform(Must be flowed type).
Thanks