travellight, I'm glad everything worked well for you, but in actuality, it was probably US you have to thank and not CO. US has been in really bad shape for several months now and in last minute situations such as yours, they'll basically take anyone's ticket, no matter what the fare paid. You said you had a discounted ticket. Well, if your ticket was non-discounted, likely any airline would take it. Depending on the circumstances, it could have been cheaper for CO to sign your ticket over to another carrier than to let you standby for the next flight.