Upgrades
 

Can someone tell me the difference in grades---y-C-O-when you buy a ticket for a fare, the agent tells you "oh you can't use your miles cause you didin't pay for upgardes, in your fare". what does she mean ? I appreciate your comments.. it seems I pick the wrong "class" :(

It simple select the eligible for Onepass upgrades box. This will only return fares that allow upgrades. (Doesn't mean there is an upgrade only that the fare allows it) If for some reason you book by phone you need to tell the agent otherwise you get the lowest priced fare which doesn't allow non-elites to upgrade.