Four months after Chinese police discovered a brothel operating inside a Hilton hotel karaokeclub and a social-action website pressured Hilton to do something about it, Hilton Worldwide says it's working on rolling out an internal code of conduct designed to prevent child sex trafficking in hotels...Also, Hilton officials have been in discussions with members of ECPAT, an internationally respected group that promotes a child-protection code of conduct to hotels, airlines and other companies...[Also refers to: Carlson, and its subsidiaries, Radisson, Park Plaza, and Country Inns and Suites; and Marriott]