Can I get someones wifi password with their ip address?

Long story short, my wifi was shut off and I have perfect sig on my Xbox to the neighbors, but they have a password. Now somehow, my iPhone connected to it with no password or anything, and I got their ip address, subnet mask, and a bunch of other stuff. I want to know if there is a way to go DOWN the stairs (metaphor), and get their password, considering I got everything else. Thank you (btw I'm not cp savvy at all so being basic would be much appreciated)

Ask them for it

No. There is no way to do that.

Pay your bills, problem solved.

No, an IP does not give the wifi password…

Obviously not. Otherwise it wouldn't be called security.

Use backtrack5, if you spend an hour reading up on it youll know what to do and how to do it