(also, i would suggest you put your name on a seperate line or after some punctuation as i don't think many people know that you add your name "ed" with no punctionation after all of your posts :) )
If you are talking about the King's Gambit Declined, then it would be after 1. e4 e5 2. f4 and then black does not take the gambited f4 pawn. Then you are "declining" the gambited pawn. Two main ways to do this is with 2...d5 or 2...Bc5
how do i play this ed