Outlook XP

I just upgraded my version of Outlook from 2000 to XP. In my Contacts folder, when I go to address an e-mail to someone, it has duplicates of each person who has an e-mail address and a fax number. I want it to display only the e-mail address whenI go to address it to that person, and not their fax number as well. So, I only want that person displayed once in my Contacts and not twice? Is there a way to go about this?