I tried asking this question on the "Simple questions simple answers thread" because I didn't want to make a new thread if I didn't need to, but my question wasn't getting answered there. Well, one person told me to use the /kickall command, but that doesn't work.
I wanted to use a command block as a sort of AFK solution for my server. I wanted to make a button that anyone could press that would give a warning first, and then kick everyone. Everyone who wasn't AFK would then just rejoin. There aren't many players on the server, so I wasn't too worried about people trolling the button, and it probably wouldn't have to be used that often either.
People see me and think I'm weak. But I can take care of myself, by myself.
These commands have been disabled for server security. I don't know of any way to enable them.
http://www.minecraftwiki.net/wiki/Command_block#Disabled_or_Unavailable_Commands
Well dang. Thanks for letting me know though.