xml.user :uid => user_block.user_id, :user => user_block.user.display_name
xml.creator :uid => user_block.creator_id, :user => user_block.creator.display_name
xml.revoker :uid => user_block.revoker_id, :user => user_block.revoker.display_name if user_block.revoker
xml.user :uid => user_block.user_id, :user => user_block.user.display_name
xml.creator :uid => user_block.creator_id, :user => user_block.creator.display_name
xml.revoker :uid => user_block.revoker_id, :user => user_block.revoker.display_name if user_block.revoker