Yesterday at the FileMaker meeting in cologne we had a nice idea. The plugin could check if you declared variables in your script before you use them.
So now we mark lines red where you use a variable name we don't see in the lines above in the same script. It was a lot of work to get this working in all the languages, but as you see below on the screenshots, it's working fine now.
Chinese traditional and simplified:
PS: Someone interested in how to make high res screenshots in FileMaker 12?