sreelakki, trust me on this. We're happy to give you flight loads around here so you know what's worth trying for, what isn't, and what you may get on with a little luck. If you must get on, don't try for UA returning. Seat maps are NOT an accurate way to look at a flight. It may be ok (still not great on some routes) to see a seat map looks full and rule it out, but NEVER go somewhere because "the seat map looks open." It will bite you in the butt eventually.