A revised Alaska Airlines and Horizon Air Reassurance Travel Policy is now in effect. You can postpone your scheduled travel without incurring the standard US$50 change fee with the following Terms and Conditions listed below:

Reassurance Travel Policy applies to all Alaska Airlines and Horizon Air tickets with flights operated by Alaska Airlines or Horizon Air in the United States, Canada, and Mexico.
Policy applies to itineraries for travel between March 19, 2003, and May 18, 2003.
Tickets must be reissued before April 19, 2003.
Customer must cancel the original reservation before the original scheduled departure date.
The US$50 change fee will be waived once per ticket.
Rescheduled travel must be completed by December 31, 2003.
The full value of the unused ticket may be used toward the purchase of a new ticket.
New ticket reservations will be subject to availability, applicable fare changes, and rules.

http://www.alaskaair.com/www2/flights/reassurances.asp