For example at CO we bid our schedule for a month at a time. At EWR on the B757 we have a 167 lines of flying in June and those lines will be awarded to a CA, and a FO in senority order with regards to choise. Once the lines are assigned we will have a opportunity to trade our trips on the computer with other pilots, or trips that were not covered due to vacations, sickness, training, etc. We have the chance to trade trips all month long, or pickup extra flying for overtime if we like. So our original line is with the same other person, however that can and often changes throught out the month.