If you have an interview or is getting close to getting one, beware! They will ask you to buy your ticket and they will 'reimburse' you. Tell them NO (you are unable, they WILL get your ticket, and no, I didn't fall for that). They will book you confirmed on OA, but your troubles may begin once you get to what ever conx city. You will be 'waitlisted'. They WILL NOT put you in First/Buisness. They WILL not Positive Space you. Anticipate getting stuck in LHR or where ever,and, upon return, expect the same mess. Could take you 2 days to get out of there! So either Tell them you want confirmed seats/seat number on GF both ways, or you should make arrangements for extended time off to get home. Also, check in for your flight on GF at least 4 hrs early if you do take the chance on standby. It also wouldn't hurt to copy their employment requirements on their website and keep that with you (they seem to forget what that is).

Cheers