MacBook connecting to wrong network? My neighbors just setup a Wi-Fi network, and my MacBook is now automatically connecting to it.


I've never manually connected to it
It has a single bar ("dot") of signal, my network has all 4


This is starting to get on my nerves, as I run lost of server software on my computer that I need access to from my other devices, and I don't want my neighbors to have access to. Additionally, I run a BitTorrent client often, and I feel bad using it on someone else's network, due to the high bandwidth usage. 

Note that I do have a terrible router that's normally sold for $10 now, and I do lose wireless for ≈ 10 seconds every hour or so, and it might see the other network as a good alternative to no network. How can I prevent it from connecting automatically, other than asking the owner to set a password?
Also note that my admin is quite paranoid, and I have very limited access to the Network. My options are "Turn AirPort Off", "Network Name", and "Show in menu bar". "Ask to join new networks" is permanently checked, and I have no advanced options. Might there be a "forget network" feature like on iOS?
If you go to Network Preferences in System Preferences, you should see a button labeled "Advanced" click on that to get to a window with many different network options. Click on Wi-Fi at the top and then rearrange/delete/add networks as you see fit. Then hit ok and you should be good to go! Depending on your OS this may not work, I have no idea. I am on Lion.