However, e-tickets are much easier to change. America West, Continental, United, US Airways, and TWA currently offer e-tickets, and more carriers are expected to follow suit in the near future. Be advised that e-tickets are not available on every itinerary. When you need to change your flight plans, we strongly urge you to work directly with the airline. Make sure that you provide the airline with your airline confirmation number.
Most airlines assess a service charge for changing a ticket.
Some airlines allow the value of an unused non-refundable ticket to be applied to the payment of higher fare for future travel. However, the airline will still charge you a service fee for the change. Some airlines waive the service fee in the event of illness or death of an immediate family member. Check directly with your airline for its policy. I've seen a better price advertised for a particular flight.