Normally, you have to purchase a qualifying fare economy ticket, which means the really cheap fares don't qualify. You have to have a valid economy seat reservation, and then you need to find an "I" category WBC seat available to be upgraded into. US to Asia round trip economy to WBC upgrades cost 50,000 miles. See http://www.nwa.com/freqfly/direct/charts/zone10.shtml
Operational (i.e., free) upgrades are usually offered only when economy is overbooked and they can move people up to the WBC area, although I think they are usually selecte by WP status, so silver would be selected after the platinums and golds. Good luck.

Edited to correct spelling. Why is it you never see it until it posts??


[This message has been edited by SeoulGold (edited 12-19-2002).]