JavaScript实现动态创建树形结构

WebFXTree.prototype.toString = function() {
            var str = "<div style='display: none;' id=\"" + this.id + "\" onclick=\"webFXTreeHandler.toggle(this);\" class=\"webfx-tree-item\" onkeydown=\"return webFXTreeHandler.keydown(this, event)\"  name=\"" + pushid(this) + "\" onMouseup=right_pop3(this)>"  +
                "<img id=\"" + this.id + "-icon\" class=\"webfx-tree-icon\" src=\"" + ((webFXTreeHandler.behavior == 'classic' && this.open)?this.openIcon:this.icon) + "\" onclick=\"webFXTreeHandler.select(this);\">" +
                "<a href=\"" + this.action + "\" id=\"" + this.id + "-anchor\" onfocus=\"webFXTreeHandler.focus(this);\" onblur=\"webFXTreeHandler.blur(this);\"" +
                (this.target ? " target=\"" + this.target + "\"" : "") +
                " [color=#FF0000]class=\"lian\">[/color]" + this.text + "</a></div>" +
                "<div id=\"" + this.id + "-cont\" class=\"webfx-tree-container\">";
            var sb = [];
            for (var i = 0; i < this.childNodes.length; i++) {
                sb[i] = this.childNodes[i].toString(i, this.childNodes.length);
            }
            this.rendered = true;
            //alert("aaaaaa/n"+str + sb.join("") + "</div>");
            return str + sb.join("") + "</div>";
        };

        WebFXTreeItem.prototype.toString = function (nItem, nItemCount) {
            var foo = this.parentNode;
            var indent = '';
            if (nItem + 1 == nItemCount) { this.parentNode._last = true; }
            var i = 0;
            while (foo.parentNode) {
                foo = foo.parentNode;
                indent = "<img id=\"" + this.id + "-indent-" + i + "\" src=\"" + ((foo._last)?webFXTreeConfig.blankIcon:webFXTreeConfig.iIcon) + "\">" + indent;
                i++;
            }
            this._level = i;
            if (this.childNodes.length) { this.folder = 1; }
            else { this.open = false; }
            if ((this.folder) || (webFXTreeHandler.behavior != 'classic')) {