If ORD is available on the 320, there are at least 2 trades posted on the bulletin board trying to get out of DEN and into ORD. When you report for new hire class, there will be a bulletin board across from the classroom in the hallway. If you don't get DEN, you can post your trade there as well. You can trade this way while in training at TK. Once you complete training then the lateral bid is your best option to transfer bases.