International Travel - Open ended airline ticket?

[janette]

My MIL is planning on going to the Phillipines in October, she is orginally from there and wants an extended visit. Some of her friends have purchased open ended tickets where they can arrange the return flight when they are ready. She is planning on at least 3 months but would really like this flexibility. I'm the one that helps her find airline deals and I don't know if this is possible to do using internet ticketing. Anyone know how to do this or is it something she'd have to arrange with a travel agent?

Thanks for your help.