Ruby on Rails 3 nested tables question

I have been happily using DHTMLXGrid on small projects for single table data collection and review.

I am now trying to implement it on a slightly more complex project on a nested table.

my problem seems to be rooted in my lack of ability to properly load data


This is the path of the xml file I am trying to use to load data.

This does not work. Any suggestions on how I might make this work?

Any kind of sample of your code and the generated xml file is appreciated.