Required library edition:
Required library file: dhtmlxtree.js

create new node as a child to specified with parentId

• parentId - parent node id
• itemId - new node id
• itemText - new node label
• itemActionHandler - function fired on node select event (optional)
• image1 - image for node without children; (optional)
• image2 - image for closed node; (optional)
• image3 - image for opened node (optional)
• optionStr - options string (optional)
• children - node children flag (for dynamical trees) (optional)