MacBook Airport Password Locked

So, lightning struck the house and killed all the electronics inside. We had to get a new wireless router, so the password changed. Unfortunately, my MacBook airport automatically uses the old password, and I can't figure out how to change it to the new one. I've tried turning the airport off and then back on, and restarting the computer, but it still signs in automatically. The bars are showing up as if it's connected, but it's not connecting to the internet. I tried Network Preferences to see if I could change the password there, but it just pops open a window without password options.

Any ideas? And thank you in advance.

You need to completely remove the old connection and start over with a new one. (create a new one) You'll also have to use the "keychain" application to remove the old password which is being remembered by the system.

Applications -> Utilities -> Keychain.app

Find your old connection and completely delete the entry from the keychain.

After setting up a new connection and password you should be able to log on automatically as before.

Regards.