Limit the number of server log in the game

Hello, everyone!
I have a personal server, and open the FLYFF, but I want to limit the number of log in my game, how do I modify the source.
Thank you for your help. . .

At the same time there is a problem, I log in the game against the designated account how to do?

There is a menu for it in the Account Server Tooltip. Have a look there or change the accountserver.ini

thanks