option buttons connected to other stuff

[obertseph]

I made a form in Access and am trying to set it up so that in one section you can choose from a list of past contacts, and if the contact isnt on that list, then you can enter in the name and adress of the new contact. So i made an option button group to select if the contact is on the list or if you are entering a new one, a drop down box that contains the past contacts, and some other text boxes so you can enter the new contact, but i have no idea how to make them all work together. Any help would be greatly appreciated