HELP!! What would I wear to a "casual outside wedding"? (Need answer ASAP)?

Ask the bride or groom what their idea of casual means.I prefer a full formal wedding as it is a formal occasion and it gives it some extra dignity.My best friend had shorts and Hawaian shirts for his best man and tail dresses for the bridesmaids.I had a tuxedo with satin bridesmaids dresses from the JC penny outlet store on the south side of Atlanta.And the groomsmen wore tuxedo's as well.I wanted to do top hat and tails,but it would have cost too much.My whole wedding had everyone of the relatives pitching in,they all wanted to help in some way.I prerecorded the reception music on some cettes and made reservations for a honeymoon cabin in the woods,with full kitchen,bathroom and fireplace at a state park lodge.We had the whole park to ourselves in February.