Hi kofispark and welcome to Daniweb. I'm sure you won't get much help regarding how you can hack a wifi from this forum. And while I'm sure that some people can hack passwords, I should think it would require a really good snippet of code and a lot of time give that passwords can contain caps, lowercase, digits, and special characters.
I do not support hacking of passwords, even if you say it's your own and you've forgotten it. For all I know it's your neighbor's password and you're looking for a free internet ride or worse.