If you have purchased your ticket vai Resident Advisor then don't worry, we will have a record of it. Just bring some ID on the night and everything will be fine.
If you have purchased your ticket vai Ticketweb, then you must get intouch with them directly and they can help.
If you purchased your ticket from Attic and it is lost, then we're afraid there's nothing we can do. Try looking down the back of the sofa x