Chat with creepy people

Been searching for a flash chat and the best one yet is develoopings chat.

It´s a chat for student at my school and it was really popular but lately there´s been problems with weird people writing all kinds of sick stuff.

To get around this I´d like there to be a registration to the chat before one can enter. I need to be able to ban people (the IP ban isn´t working to good due to proxys I think?)

Have found a couple but they where so buggy that I could not handle them. It is important that I can ban people.

It doesn´t have to be a flash chat though I find it easier to adjust their interface to the kids liking.

Any ideas


ps. I do have access to MySql and PHP and have the basic skills to set the chat up, but I don´t manage to create a chat on my own.