@Shining Riku, Thanks, I'm glad it works well for your Final Fantasy game. I based it on the FFTA class system, because I originally planned to use it in my own game. And I had no idea that you could use it in a combination with the RO Job/skill system. That's cool that they work together. Huzzah for aliasing.
and as for that message box...that was there for debug purposes, I can't believe I forgot to take it out. Thanks for pointing that out, lemme tell you how to fix that, give me just a second.
-edit, it looks like it's fixed in the latest version. (at least the posted version of the script, I don't have RMXP on this comp right now). Try updating script versions, and see if the message box still pops up. If so, that means I don't have the same version of the script in the demo that I have posted on the topic. If that's the case, I'll hunt down a computer with RMXP (my regular comp is elsewhere) and find the line that causes that little message box to pop up. Sorry for the inconvenience, I can't believe I didn't take out the debug line.