I am flying Ethiopian airlines on a codeshare booked on United from ORD to JRO through IAD. I have the Ethiopian record number and when I go to the Ethiopian site, I can see the flight (and my record), but there does not seem to be anywhere to choose seats online. Does anyone know of a way to do advanced seat assignment? I am United *G and am trying to figure out if I can get any kind of preferred seat, even if just an aisle seat prior to checking in. I am flying economy. Thanks for any info.