Dear nGrinder user.
We're about to release nGrinder 3.2.
Before than, we migrate the existing ngrinder-demo machine to 3.2 version.
http://ngrinder-demo.nhnopensource.org/ (ID : user / PW : user)
Please try Groovy Scripting there. We believe Groovy support changes whole performance testing experiences. You can even use Eclipse to debug nGrinder Groovy Script.
You can refer the how Groovy script is working in the following link.
http://www.cubrid.org/wiki_ngrinder/entry/groovy-script