Connected but not really

[JOHNHAGEN]

I have been using a Netgear WG 121 usb adapter to connect to the internet wirelessly for quite a while with no problems and then this weekend it just won't work any longer. It still shows both my network and my neighbors and even says it is connected(green light and medium to strong signal) However neither of the networks will actually connect me to the internet. I had not been messing around with the connection before this, it just seemed to occur on its own. Any advice on how to fix this or what happened?