Iin dayo / daijobu

I came across both terms and can't see the diffrence yet. Both get's translates as 'It's fine/okay'. In which situation is it better to use one or the other?

Both can come out as "no problem," "it's fine," "don't worry," etc. in English :)

"Daijoubu" is the answer you give when someone is concerned about *you* and asks you a question if *you* are alright, if things are OK with *you*, if things work out for you, etc., and you reassure that *you* are OK.

For example, you stumble on the street and fall, then your friend asks:
- Kega wo shinakatta? (You didn't hurt yourself?)

Your friend and you spent some time together in a coffee shop chatting, and
whoops! it's time for you to go to an appointment soon, so your friend asks:
- Jikan ni maniau? (Are you going to make it in time?)

....then you say "daijoubu."

"Iin dayo" (particularly with that "...yo" ending) can be used when reassuring the other party that he/she hasn't done anything wrong, for example, in response to an apology for something he/she's done. That's one example that comes to mind.

"iindayo" is often used in the context of treating your friend, etc.(informal) at restaurant, etc. and you pay the bill for him/her.
He/she would say "warikan ni shimasho (ka)?(let me pay my half (?), then you say "iindayo or iiyo, daijyobu (no, you don't have to or it's ok, no problem or no worry). Boku (Watashi) ga ogorukara or boku no ogori (this is my treat).

Thanks alot for your help there. It's really usefull to get examples how to use this sentences. Once again thanks for your help.