How to tell when someone was last online facebook?

[JMc]

OK. My friend uses a computer for facebook so then when they aren't online that means it won't say "last active". I haven't talked to them in a while and would really like to. The problem? They live in Spain... he is my BFF and I can never get ahold of him! If I message him sometimes (he's only missed my messages 2x) but every other time I've been able to say "oh hey!" How can I tell when they're last online facebook? And how can I make sure they see my message... I honestly just think he doesn't notice the notification go off.... I really miss him and talking to him so can I please get some help? Honestly I missed him by 10 seconds today. I was all happy sent a message saying "hi" and right as it sent he went offline... I'm pretty sad about this.... I will see him next summer at this summer camp we actually met at this year if worse comes to worse but I don't want to be like "oh hey..." after 10 months... ANYWAYS he only goes online (from what I have noticed) once every like 5-8 days... Help??