Required library edition:
Required library file: dhtmlxlayout.js / dhtmlxaccordion.js

attaches dhtmlxTree to the cell, returns tree object

Attaching to the layout's cell:

    var dhxTree = dhxLayout.cells("a").attachTree(); // returns tree object

Attaching to the accordion's cell:

    var dhxTree = dhxAcc.cells(id).attachTree(); // returns tree object