How to get this Wi-Fi password

I have had an iPad. I somehow figured out the Wi-Fi password from my neighbors upstairs. I just got an iPhone 5 today and I can't remember what the Wi-Fi password is to connect it, and my iPad won't show the password so how do I figure this out? I can't set my own up since I don't have a computer in my own house.

Well there's not really a way, unless you get a hacking program from the web (which is not a good idea BTW). You can ask the neighbors for the internet maybe?