Online Travel Booking and Bidding Agencies - How to book same flight going 1 way, but different dates going back

Sorry the title doesn't make much sense, but basically me and 4 friends are going to la in the summer, 2 of them want to stay longer. With online sites how do I do this? I know I can do it separately, but what if the flight going to la get full? Then were screwed, can I call any of the sites?

No way to do it as one reservation.... you would have to do two different reservations.

Only option... if you want to ensure all 5 people are on the same flight going out is to call the airlines/agency and book directly.

You could also have two windows open and book both at the same time... to see if you can get five seats at the same time.

William

Or , if you are booking a flexible ticket ( no "change fee"), you can book all online and then call the agency/airline to change the dates. Obviously, you still need to check avilability first.

One person can make their reservation first and then tell the other 4 the airline and flight number(s) (possibly codeshare number) and book accordingly.

The best way to do this would be to purchase 2 sets of itineraries with 2 passengers each and make sure the outbound flights are exactly the same (double-check the flight numbers). Then contact all the affected airlines after purchase to have them make notes on each airline record in their system(s) that all of you are travelling together. If concerned about not having enough seats for all 4 passengers on the outbound flights then it depends on who you're booking through on how you could determine how many seats are left but the best way would be to purchase them one right after the other.