It appears to be a problem with your internet (or anything inbetween your home and the server your internet goes through to connect), nothing we can do about.
MaxToMinimum, restart your computer first of all. If that doesn't work, reset your internet router (ask your parents if you don't know how to do that). I've gotten problems like these before, usually restarting fixes it. If not, I'd just wait until tomorrow to try logging on. The problem will probably disappear overnight. If you urgently need to get on, you might want to google your error message and search for fixes.
Ok, thanks! btw EcoCItyCraft has a different thing before its name (You know that square infront of the server name) It is for another server in my server list. Why would that be?
The netherstar image next to the name? That's a 1.7 feature, servers can have an image next to their IP.
Max, Unfortunately this it out of my realm of expertise. My best advice is to search your error in google and see if you can find a fix. Check out this link, it will take you to my search, maybe you can find a solution there.
A while ago I had an issue like this. I could join a few servers just fine but the others I couldn't. Last time this happened it took about 2-3 days to work and my friends at school had the same issue. Just wait it out and it should be fixed.