Required library edition: 
 Required library file: dhtmlxtree.js
set images used for parent-child threads drawing (lines, plus, minus)
 arrayName - name of array: plus, minus
 
 image1 - line crossed image
 
 image2 - image with top line
 
 image3 - image with bottom line
 
 image4 - image without line
 
 image5 - single root image