Help with my EVO and Facebook?

When we first got the phone my husband was on his facebook, and i'm not sure how he done it but he synced his facebook friends birthdays to the calendar on the phone. Well, I looked it up and found out how to take them off the calendar, but when I go back in settings on the calendar his name is the only one under Facebook. I'm just wondering if there is anyway to change it where I can sync my friends to the calendar instead of his, or possibly both of ours. I think you can check more than one calendar at the same time, but my name doesn't show up on the calendar options..Does anyone know how I can put my facebook on there also? Thanks.