gistfile1.txt

 if (treeData == null) {
        var treeData = Ext.Ajax.request({
            method: 'GET',
            url: '/Dashboard/GetNavigationData',
            success: function (response) {
                treeData = Ext.util.JSON.decode(response.responseText).results;

               
                var list = [];
                var treeNode = newTree.getRootNode();
                for (i = 0; i < treeData.length; i++) {
                    var newChild = {};
                    newChild.Id = treeData[i].Id;
                    newChild.text = treeData[i].text;
                    newChild.iconCls = treeData[i].iconCls;
                    newChild.leaf = treeData[i].leaf;
                    newChild.children = {};
                    if (i == treeData.length)
                        newChild.isLast = true;
                    else
                        newChild.isLast = false;
                    if (i == 0)
                        newChild.isFirst = true;
                    else
                        newChild.isFirst = false;

                    if (treeData[i].children.length > 0) {
                        
                        for (j = 0; j < treeData[i].children.length; j++) {
                            newChild.children.text = treeData[i].children[j].text;
                            newChild.path = treeData[i].children[0].path;
                            newChild.children.path = treeData[i].children[j].path;  
                            newChild.children.Id = treeData[i].children[j].Id;
                            newChild.children.iconCls = treeData[i].children[j].iconCls;
                            newChild.children.parentId = treeData[i].children[j].ParentId;
                            newChild.children.leaf = treeData[i].children[j].leaf;
                        }
                    }
                    treeNode.appendChild(newChild);
                    Ext.getCmp('Dashtree2').getView().refresh();
                    debugger;
                }
                navigationStore.loadData(treeData);
                navigationStore.sync();
            }
        });
    }