Wifi will no longer connect

I have wifi at home and for the first couple of months that I had my phone, the wifi would connect easily. For the past week or so, wif will not connect. I will go into the wifi settings on the phone and choose the network manually, it'll say "Obtaining IP address from... " then after a while will just say "Disabled" and won't connect.

My husband got the exact same phone a few months before I did and the same thing has happened to him - not at the same time.

P.S. We've tried re-setting the router, no luck.

Help!