<div id="treeboxbox_tree" style="width:200;height:200"></div>
<script>
 
    tree=new dhtmlXTreeObject("treeboxbox_tree","100%","100%",0);
        tree.setImagePath("../imgs/");
        tree.enableSmartXMLParsing(true);     //enable smart parsing    
        tree.loadXML("tree.xml");
        ....
        //sorting
        function sort_func(a,b){
            a=(tree.getItemText(a)).split(" ")[1]||"";
            b=(tree.getItemText(b)).split(" ")[1]||"";
            return ((a>b)?1:-1);
        }
        tree.setCustomSortFunction(sort_func);
        tree.sortTree(tree.getSelectedItemId(),'ASC',1);
        tree.sortTree(tree.getSelectedItemId(),'DES',1);</script>