Collapse/expand child nodes of tree in d3.js?

Question

I\'m building a tree structure (or rather modifying one of the examples with a set of my own data in my own json) and I\'m trying to create some functionality:

My tr

Answer 1

There's this:

http://mbostock.github.com/d3/talk/20111018/tree.html

There are a number of other interactive hierarchical layout examples from my SVG Open keynote.